Tata Steel is putting its entire UK business up for sale
The business case for making steel in Britain has "rapidly deteriorated" due to falling prices and rising costs, the Mumbai-based company said in a statement.
"These factors are likely to continue into the future and have significantly impacted the long term competitive position of the UK operations," the company said.
The company said it would "explore all options for portfolio restructuring including the potential divestment of Tata Steel UK, in whole or in parts."
The move caused an outcry from Community, the steelworkers' union, which demanded a meeting with Prime Minister David Cameron to discuss Tata's move.
Community general secretary Roy Rickhuss said: "The UK is now on the verge of a national crisis. Tata Steel withdrawing completely from the UK risks destroying our entire steel industry. That would be a disaster both for those communities reliant on steel jobs and our entire industrial base."
Worst affected is Port Talbot in Wales, one of the UK's biggest steel plants. Politician Leanne Wood, leader of Welsh party Plaid Cymru, called the news "devastating."
According to Bloomberg, Tata Steel reported a fiscal third-quarter loss of 21.3 billion rupees ($320 million) in February, versus a profit of 1.57 billion rupees a year earlier.