Royal Bank of Scotland’s £7bn ($13.6bn) auction for its UK insurance business has received a lukewarm response from potential buyers, with Warren Buffett’s Berkshire Hathaway pulling out of the bidding and there are doubts over the level of interest from Germany’s Allianz.

RBS has targeted eight potential trade buyers, including American International Group, Allstate and Travelers of the US, Generali of Italy, Zurich Financial, and the Chinese insurer Ping An. The sale is part of its plans to bolster a balance sheet weakened by mortgage-related writedowns.