Lloyd's of London, the centuries-old insurance market, argued Wednesday that Britain's continued EU membership would be the "better outcome" for the group in the looming June referendum.
Lloyd's, which made the comments in its annual report alongside news of tumbling 2015 profits, added that it was making contingency plans for a so-called Brexit.
Britons are set to vote in a crucial referendum on June 23 to decide whether to remain part of the European Union.
Pre (Shanghai: 600048.SS - news) -tax profits sank 30 percent to £2.1 billion ($3.0 billion, 2.7 billion euros) last year compared with £3.0 billion in 2014, amid "challenging" conditions, the company added on Wednesday.
The performance was hit by low interest rates, and low investment returns -- which sank to £400 million from £1.0 billion last time around.
"Uncertainty over the United Kingdom's membership of the European Union adds an unsettling ingredient to the mix.
"We believe strongly that continued membership would be the better outcome for Lloyd's and the businesses in our market but we are preparing contingency plans in the event of an exit."
Lloyd's added that it wanted to ensure continued access to the European Union, which is the world's largest insurance market.
"The global economic outlook remains challenging," the company said.