LONDON — Lloyds Banking Group said on Thursday that it would cut an additional 3,000 jobs and close 200 more branches by the end of next year, as it warned that Britain’s decision to leave the European Union could slow the country’s economy.

The retail and commercial bank, which is partly owned by the British government after a bailout during the financial crisis, said that the economic outlook for Britain was uncertain after the outcome of the June 23 referendum to leave the bloc, or “Brexit,” but that “a deceleration of growth seems likely.”

Lloyds said it planned to cut annual costs by an additional 400 million pounds, or about $525 million, by the end of next year. Beyond the job cuts and branch closings, the bank said it would sell other properties it owns. Lloyds had 74,117 employees as of June 30.

It originally announced plans in 2014 to reduce costs by £1 billion by the end of 2017, in part by eliminating 9,000 jobs.