March 28 (Reuters) - British North Sea-focused oil producer EnQuest narrowed its annual loss to $30.8 million last year, down from a $41.2 million loss in 2022, it said on Thursday.

The company also announced its first shareholder return in the form of a $15 million share buyback this year.

The company said it posted a loss after tax due to the energy profit levy (EPL) which was extended by one year by British finance minister Jeremy Hunt earlier this month.

EnQuest has for years been shielded from UK taxes as it could offset bills against reported tax losses, which stood at $2 billion at the end of 2023.

"The EPL has resulted in a number of industry participants accelerating their shift in focus away from the UK North Sea," said Chief Executive Amjad Bseisu.

"Our significant tax loss position and the impact of the EPL on marginal tax rates means that the transfer of assets to EnQuest ownership would increase their relative value to a multiple of that in the hands of existing owners."

In December last year, Enquest appointed Jonathan Copus as its finance chief to succeed Salman Malik, who will become the CEO of Veri Energy, its new energy and decarbonisation unit.

The unit is managing work projects on the company's Sullom Voe Terminal that would "crystallise significant operating cost and emission reductions in 2026 and beyond", EnQuest said.

EnQuest lowered its net debt by 33% to $480.9 million as of end-2023, versus $717.1 million in 2022.

It reiterated it expected to invest about $200 million this year, with operating costs of $415 million and decommissioning spending of $70 million.

Last month, EnQuest said it produced 43,812 barrels of oil equivalent per day (boe/d) last year, in line with guidance of 42,000-46,000 boe/d, but down from 47,259 boe/d in 2022.

The company projected output between 41,000 and 45,000 boe/d this year. (Reporting by Deep Vakil in Bengaluru; Editing by David Goodman and Emelia Sithole-Matarise)