Net profits at the sustainable investment manager founded by the former head of Goldman Sachs Asset Management and ex-US vice-president Al Gore roughly halved to a more “normal” level in 2012 from the previous year’s total, when figures were boosted by high performance fees.

Profits at Generation Investment Management, which was set up in 2004 by former GSAM executive David Blood, Gore and Mark Ferguson, the son of former Manchester United manager Sir Alex Ferguson, fell by 48.5% to £26.1 million in 2012 from £50.6 million the previous year, according to the firm's latest accounts filed at Companies House.