LONDON, March 1 (Reuters) - Britain said on Wednesday it would extend anti-dumping measures on Chinese reinforcement steel after its Trade Remedies Authority (TRA) reversed an earlier recommendation to drop the duties.

The TRA last year recommended that the measures, which have been in place since 2016, should be dropped, given high demand for reinforcement steel from Britain's construction sector and a fall in supply from Russia, Belarus and Ukraine. It said maintaining the duties would keep prices high and damage the economy.

But on Wednesday, the government body said new data showed imports from other countries were filling the gap in supply of the steel, known as HFP Rebar, caused by the drop from Russia and Belarus since the start of the Ukraine war.

Business and trade minister Nigel Huddleston said Britain wanted to prioritise "protecting UK steel from unfair competition".

"This decision will help our strategically vital steel industry, which supports tens of thousands of jobs, to stay competitive," he said in a statement.

Last week British Steel, which is Chinese owned, said it would cut 260 jobs as steelmaking in Britain was uncompetitive.

The extension of the anti-dumping duties, which allow a country to take action against goods sold at less than their normal value, runs until July 2026.