(21) Business Segments The Company measures segment profit as operating income for Petroleum and Nitrogen Fertilizer, CVR's two reporting segments, based on the definitions provided in ASC Topic 280   Segment Reporting . All operations of the segments are located within the United States. Petroleum Principal products of the Petroleum Segment are refined fuels, propane, and petroleum refining by-products, including pet coke. The Petroleum Segment's Coffeyville refinery sells pet coke to the Partnership for use in the manufacture of nitrogen fertilizer at the adjacent nitrogen fertilizer plant. For the Petroleum Segment, a per-ton transfer price is used to record intercompany sales on the part of the Petroleum Segment and corresponding intercompany cost of product sold (exclusive of depreciation and amortization) for the Nitrogen Fertilizer Segment. The per ton transfer price paid, pursuant to the pet coke supply agreement that became effective October 24, 2007, is based on the lesser of a pet coke price derived from the price received by the Nitrogen Fertilizer Segment for UAN (subject to a UAN based price ceiling and floor) and a pet coke price index for pet coke. The intercompany transactions are eliminated in the Other Segment. Intercompany sales included in petroleum net sales were approximately $11.4 million, $4.3 million and $6.1 million for the years ended December 31, 2011, 2010 and 2009, respectively. The Petroleum Segment recorded intercompany cost of product sold (exclusive of depreciation and amortization) for the hydrogen sales described below under "Nitrogen Fertilizer" of approximately $13.2 million, $(1.6) million and $(0.8) million for the years ended December 31, 2011, 2010 and 2009, respectively. Nitrogen Fertilizer The principal product of the Nitrogen Fertilizer Segment is nitrogen fertilizer. Intercompany cost of product sold (exclusive of depreciation and amortization) for the pet coke transfer described above was approximately $10.7 million, $4.0 million and $7.9 million for the years ended