Rishi Sunak becoming Britain's next prime minister will help stabilise markets after a period of turmoil, but his new team should ensure it is focused on keeping London competitive as a global financial centre, the CEO of lender HSBC said.

Sunak has said the country faces a "profound economic challenge", after being chosen by the ruling Conservative party to lead the country. He is set to be appointed prime minister by King Charles later on Tuesday.

Sunak will be tasked with rebuilding Britain's financial credibility, after his predecessor Liz Truss triggered a crisis of investor confidence with plans for vast unfunded tax cuts.

"We're very pleased that there has been a decision taken on the UK Prime Minister position, that now allows the markets to stabilise as you can see in the way the markets reacted yesterday, that's positive," HSBC CEO Noel Quinn told Reuters, after the bank posted third quarter earnings.

Sunak's successful bid to become prime minister after rivals pulled out has relieved some of the nervousness around the outlook for the UK economy, analysts said, boosting domestic markets and easing borrowing costs.

Quinn said Sunak's government should work with the financial industry to ensure Britain's regulatory environment remains globally competitive, while not sacrificing its reputation for prudence.

"There are some areas where I think there is potential for improvement to drive greater competition," Quinn said, adding that he welcomed moves to embed competitiveness into regulators' objectives.

"It's important for the City of London to remain competitive with regulatory environments around the world." (Reporting by Lawrence White; Writing by Iain Withers; Editing by Muralikumar Anantharaman)