Russia's state-owned Rosneft teamed up with U.S. company ExxonMobil on Tuesday to develop huge offshore oil fields in the Russian Arctic in return for access to resources in the Gulf of Mexico. 
 
 Because Rosneft does not have its own technology for deep sea drilling, it was looking for partners to develop the offshore projects in the Arctic and other regions of Russia. A deal it was pursuing with Britain's BP earlier this year, however, fell through. 
 
 Rosneft spokesman Rustam Kazharov told the Associated Press that the "strategic partnership" with Exxon was signed in the presence of Prime Minister Vladimir Putin. 
 
 He was unable to name the plots that Rosneft will work on in the Gulf of Mexico and Texas. 
 
 ExxonMobil said in a statement that Tuesday's agreement includes $3.2 billion to be spent on exploring three sectors in the Kara Sea in the Arctic as well as a sector in the Black Sea. 
 
 Rex Tillerson, ExxonMobil's chief executive, attended the ceremony and said in the statement that the deal "takes our relationship to a new level and will create substantial value for both companies." 
 
 ExxonMobil and Rosneft first struck a deal in January to develop a sector in the Russian part of the Black Sea. 
 
 Putin lauded Exxon for its extensive experience in drilling in the Arctic region in Canada. 
 
 Tuesday's signing ceremony was preceded by talks between Rosneft executives and ExxonMobil top brass, including President Neil Duffin. 
 
 Putin hailed the deal as "a truly strategic partnership", the RIA Novosti news agency reported. The prime minister estimated the total investment in the project at a massive $500 billion, a figure he described as "scary." 
 
 The deal is a blow for Britain's BP, with which Rosneft struck an accord in January to jointly develop the Arctic fields. That agreement fell through, however, after BP's Russian shareholders managed to block it. 
 
 "The Exxon deal is offering us much more" than BP, Kazharov told the AP. 
 
 BP's spokeswoman Sheila Williams would not comment on the deal but said BP is still "committed both to Russia and to the continuing success of TNK-BP," its Russian venture. 
 
 ____ 
 
 Meera Selva contributed to this report from London. 

 An employee works near a gasoline tank truck outside the Rosneft Achinsk oil refinery plant, one of the biggest Siberian fuel suppliers, near the town of Achinsk, some 117 miles west of Krasnoyarsk, April 28, 2011. 
 
 SOCHI, Russia/SAN FRANCISCO | 
 
 SOCHI, Russia/SAN FRANCISCO (Reuters) - Exxon Mobil Corp and Rosneft signed an agreement to extract oil and gas from the Russian Arctic, in the most significant U.S.-Russian corporate deal since U.S. President Barack Obama began a push to improve ties. 
 
 The pact, which includes an option for Rosneft to invest in Gulf of Mexico and Texan properties, ended any hope of Britain's BP reviving its deal with state-owned Rosneft to develop the same Arctic territory. That deal was blocked in May by the billionaire partners in another BP Russian venture. 
 
 The pact gives Exxon, the biggest U.S. oil company, access to substantial reserves in Russia, the world's top oil producer. For Rosneft, it's about bringing in one of the few companies capable of drilling in the harsh, deep waters of the Arctic. 
 
 Russia has shown greater willingness in the past year to secure foreign partners, even if some deals later fell apart. The Exxon announcement comes only months after the demise of a Rosneft deal with Chevron Corp for a $1 billion investment in an estimated $32 billion Black Sea project. 
 
 Analysts cited differences between Chevron and Rosneft over the choice of contractor, the joint venture's domicile and the jurisdiction of arbitration for any business disputes. 
 
 Yet Chevron, like Royal Dutch Shell Plc, was also considered a potential partner for Rosneft's Arctic venture. 
 
 Russian Prime Minister Vladimir Putin attended the Tuesday signing -- in the Black Sea resort of Sochi -- by Exxon Chief Executive Rex Tillerson and Russia's top energy official, Deputy Prime Minister Igor Sechin. 
 
 "New horizons are opening up. One of the world's leading companies, Exxon Mobil, is starting to work on Russia's strategic shelf and deepwater continental shelf," Putin said. 
 
 Exxon and Rosneft agreed to invest $3.2 billion to develop East Prinovozemelsky Blocks 1, 2, and 3 in the Arctic Kara Sea and the Tuapse licensing block in the Black Sea. 
 
 Rosneft will own 66.7 percent and Exxon the rest of the joint venture to develop the blocks, which Exxon said were "among the most promising and least explored offshore areas globally, with high potential for liquids and gas." 
 
 "The fact that someone with the stature of Exxon Mobil is willing to give it a stab is very significant," said Amy Myers Jaffe, of the Baker Institute at Houston's Rice University. 
 
 While Rosneft will tap Exxon's expertise to open up one of the last unconquered drilling frontiers, it will also diversify further by getting a piece of some of Exxon's U.S. developments. 
 
 "To get into Russia offshore you give up some of your domestic offshore. I think it's a fair trade," said Brian Youngberg, senior energy analyst at brokerage Edward Jones in St. Louis, who has a "hold" rating on Exxon shares. 
 
 It marks a big move for Exxon after it spent a year swallowing XTO -- a much-criticized purchase that shifted its profile toward the depressed U.S. natural gas market. "Now Exxon Mobil is starting to look elsewhere for deals," Youngberg said. 
 
 Analysts also said the Rosneft-Exxon agreement indicates that the reset in relations Obama sought was working to reduce the political risk for U.S. businesses operating in Russia. 
 
 "Three years ago, American companies were being excluded. Here, an American company is at the center of a flagship announcement. This deal demonstrates that reset has had a positive effect on U.S.-Russia energy relations," said Cliff Kupchan, director of Eurasian Practice at Eurasia Group. 
 
 In explaining the deal's significance, Myers Jaffe pointed to previous failed efforts in the past decade to foster joint energy interests. "There was a lot of disappointment on both sides," she said. "The U.S. industry just gave up on Russia." 
 
 PLAN B FOR ROSNEFT 
 
 Rosneft said the Kara Sea blocks contain an estimated 36 billion barrels of recoverable oil resources. Total resources are estimated at 110 billion barrels of oil equivalent -- more than four times Exxon's proven worldwide reserves. 
 
 The Black Sea block is estimated to hold 9 billion barrels of oil reserves. First drilling is planned to start in 2015, with Exxon shouldering most of the costs. 
 
 "The Russians very quickly had a Plan B, and Plan B was Exxon," said Fadel Gheit, energy analyst at Oppenheimer & Co, referring to the quick switch to Exxon from BP. 
 
 The deal marks a turnaround in Russia for Exxon, which was widely thought to be on the verge of taking over Yukos, then Russia's largest oil company, before Yukos's boss, Mikhail Khodorkovsky, was arrested in 2003. 
 
 Khodorkovsky was subsequently jailed for fraud and tax evasion and Yukos's prime assets were bought at bankruptcy auctions by Rosneft, now Russia's industry leader and with enough reserves to cover 27 years of production. 
 
 Uncertainty persists over whether Putin or President Dmitry Medvedev will seek the presidency next March. Putin can now show off the deal as a success if he decides to run. 
 
 The transaction also marks a comeback for Sechin, who was ousted as Rosneft chairman earlier this year in a purge of state company boards ordered by Medvedev. Sechin estimated total investment in the project at $200 billion-$300 billion. 
 
 In anticipation of all the money flowing there, oilfield services companies including Schlumberger Ltd, Baker Hughes Inc and Weatherford International Ltd WFT.N> have been picking up assets in Russia. 
 
 Environmental concerns are unlikely to create barriers to oil extraction in Russia's remote Arctic regions, if moves this year by the country's Natural Resources Ministry to shift nature reserve boundaries are any guide. 
 
 U.S. UPSTREAM 
 
 Rosneft will be offered an equity interest in Exxon exploration projects in North America, including deepwater Gulf of Mexico and fields in Texas, as well as in other countries. 
 
 The deal thus fulfills a demand for reciprocity often made by Putin, helping Rosneft, which already works with Exxon offshore Russia's Sakhalin island, toward its long-term goal of being a global energy major. 
 
 It was not clear whether any such investments by Rosneft would need approval from the Committee on Foreign Investment in the United States. An Exxon spokesman declined to comment. 
 
 There is no exchange of equity in the agreement, while the BP deal called for a $16 billion share swap in which BP would have exchanged a 5 percent stake for 9.4 percent in Rosneft. 
 
 "Exxon is double or triple the size and market value of BP," said Gheit at Oppenheimer. "So, obviously, this would be much more important for a BP than it is for Exxon." 
 
 While Rosneft shares rose 1.4 percent in Moscow, Exxon fell slightly on the New York Stock Exchange on Tuesday. 
 
 (Additional reporting by Vladimir Soldatkin, Katya Golubkova, Michael Erman and Ernest Scheyder; Writing by Douglas Busvine and Braden Reddall; Editing by Dan Lalor, Tiffany Wu, John Wallace, Steve Orlofsky and Phil Berlowitz)
– Exxon Mobil scored a major coup in the search for Arctic oil today, signing a deal with Russia to explore areas with state-owned Rosneft, reports Reuters. The deal gives Exxon access to spots controlled by Moscow in the Kara Sea, which has become a much sought-after region within the petroleum industry now that sea ice looks to be receding, notes the New York Times. As part of the deal, Exxon will give Rosneft a stake in some US operations in the Gulf of Mexico and Texas. Rosneft was seeking out an offshore partner because it doesn't have its own technology for deep sea drilling, and the agreement comes after a similar deal between Rosneft and BP fell through. The Wall Street Journal sees it as a "big win" for Exxon in the race to lock down potential fields. Vladimir Putin estimated that the total investment in the project could be a "scary" $500 billion, notes AP.