Rothesay Life, the UK insurance group Goldman Sachs set up 12 years ago to acquire company pension funds, has announced it will raise a fresh £500m from its backers to finance further expansion in a booming market.

The insurance group, which now manages £42bn, said in a trading update on September 10 it had taken in £3.7bn of new pension business in the first half of the year — a drop from £12.4bn during the same period a year ago, but that included a single deal to acquire £12bn of annuities from Prudential.