Julian Roberts, the new chief executive of Old Mutual, has given himself two months to sort out the problems at the insurance giant's US life division before deciding whether to put the struggling unit up for sale.

Speaking to The Times on his first day in the job, Mr Roberts also signalled that he was prepared to push through an executive reshuffle at Old Mutual in the wake of a fresh bout of troubles at the American unit.

He said that fixing the problems that have bedevilled the American operations was his “No 1 priority”. He refused to rule out further writedowns against hedges on guaranteed annuity policies that have gone wrong.

“My agenda is to get to the bottom of the issues in the Bermudan business [where the problematic investments were written]. I want the work finished within 60 days. Once we have drawn a line under the issue, all options would then be open,”

Mr Roberts said. Selling the American division was a possibility, but nothing had yet been decided, he said.

Mr Roberts, who was born in Croydon, South London, becomes the first non-South African to take charge at the insurer since it was founded as a member-owned organisation in 1845. The former boss of Skandia, which was bought by Old Mutual two years ago, Mr Roberts was promoted after the surprise resignation of Jim Sutcliffe.

Mr Sutcliffe, who had run the business for eight years, resigned on Tuesday just as Old Mutual was preparing to brief investors about further losses in the US life business.

It said yesterday that it had discovered an exposure of $155 million (£88.2 million) against guaranteed annuity products sold to Asian investors that it had failed to hedge properly.

It came barely a month after Old Mutual disclosed £107 million of losses against the botched hedges and admitted that it would need to inject £150 million into the business. A further $250 million of capital was set aside as a reserve against the American life unit yesterday.

In addition, Old Mutual wrote down $135 million against the value of preferred shares that it held in Fannie Mae and Freddie Mac, the two American home loan providers that were nationalised this week. Since the nationalisation, the value of Old Mutual's shares, held in the US life book, have slumped.

Mr Sutcliffe, a popular executive internally, becomes the first British-based boss since the onset of the credit crunch to resign voluntarily in the wake of related losses. He is understood to be entitled to 12 months' pay, about £800,000, in lieu of notice, having left the insurer with immediate effect.

Mr Roberts said that Mr Sutcliffe “did the honourable thing” by resigning. He said that it was too early to detail his strategy, but signalled that he was willing to overhaul management as part of a move to sharpen up internal controls.

“I may well end up making changes to the way the group operates. In particular, risk management, governance and oversight need to be a lot stronger at the centre.”

Times Recommends

• Minister in talks with Saudis to protect creditors
• Premier Inn hits back in £29-a-room row
• Bankers hit back at 'populist' bonus supertax