Californiaâ??s largest public pension fund has agreed to buy a 9.9 per cent stake in Silver Lake Partners, the large US private equity group.

It is rumoured that the California Public Employees Retirement System, which manages more than $250bn in assets, will take the minority stake in Silver Lake in exchange for an undisclosed amount of money and a seat on the firmâ??s advisory board.

Calpers has also agreed to make further commitments to Silver Lake funds, whose investments are focused on the technology industry. The deal is expected to be announced on Wednesday.

The California pension fund recently increased its allocation to private equity from 8 to 10 per cent.