Tata: What the steel plants around Wales do
Tata Steel has five sites in Wales, employing about 6,800 workers - with the company in the process of reducing that to 6,250. There are another 6,600 workers at eight plants in England.
Employment: 4,104 workers.
What does it do? The largest steelworks in the country and is the only plant left in Wales making steel from scratch. It produces slab, hot-rolled and cold-rolled steel plus galvanised coil.
Reaction: Unite union secretary and steelworker Mark Turner said it was a crazy situation the place which made the "best steel in the world" may no longer have a long-term future.
"We were really surprised by the announcement because the one thing that the company told us that would not happen is that they would put us up for sale."
Actor Michael Sheen, still with a close connection to the town he grew up in, said: "Welsh and UK government must do all they can now to show support for steelworkers in Port Talbot and across the UK.
"Steel industry hit hard by '08 bank crisis. Hope as much support for steel industry and workers now they face their time of greatest need."
Employment: 649 workers
What does it do? Produces tinplate and other packaging steels - including for the food and drink industry. It also has cold-rolling facilities.
Reaction: Carmarthenshire council leader Emlyn Dole said the community was concerned as hundreds of jobs depended on it but the plant was modern and "should have a viable future".
Llanelli AM Keith Davies accused the UK Government of "repeated inaction" and said it was important that the "voice of steelworkers and the interests of our local economy" were the main priorities.
Employment: About 1,000 workers (1,314 including Newport Orb).
What does it do? The sister plant to Port Talbot, it rolls the steel which the larger plant produces. Galvanises steel for the car industry and products like washing machines. Part of the works - the hot and cold-rolled strip mill - was mothballed last summer with the loss of 250 jobs.
Reaction: Reg Gutteridge, union official believes the site could be sold off separately because of its strong automotive line. He says workers are shocked and disappointed.
Labour MP for Newport East Jessica Morden called the plant "world class" and said nationalisation could be a solution in the short to medium term, while longer term solutions are found.
Employment: Estimated at between 300-350 workers
What does it do? Grain-oriented electrical sheet steel, produced by Cogent Power, a subsidiary of Tata. The material is used in generators, transformers, motors and magnetic products. The factory, based near Newport's transporter bridge, dates back to 1898.
Employment: 727 workers
What does it do? The main steel-making works closed under British Steel in 1980 with the loss of 6,500 jobs but the remaining plant produces galvanised and colour-coated coil. Business is doing so well it was not included in the recent jobs cuts package.
Reaction: Keith Jordan from the Community Union said Shotton is already profitable by itself. He says workers there will be facing a tough time in the next few weeks as they deal with the uncertainty and the need to keep producing a quality product.
Conservative AM Mark Isherwood said it was a deeply worrying time.
"Support from the Welsh and UK Governments will be critical in achieving the future of steel in North Wales - and the workers at Shotton deserve nothing less than to see every possible avenue explored."
Local AM Carl Sargent said he hoped the possibility can be explored of selling the Shotton site as a going and viable concern - separately from what happens to Port Talbot if need be.
"I vividly remember the impact of the high level of redundancies we experienced here in Deeside in 1980," he said.
"The Shotton group is still profitable and it must be safeguarded and jobs protected."