UK buyout firm Permira could face a fundraising crunch after its largest investor said it might be unable to commit to new funds for up to two years, forcing it either to go ahead with fundraising without the investor, or to keep a tight rein on its pace of investment.

Permira faces the dilemma because its €9.6bn ($12.4bn) fourth fund is slightly under 60% invested and it would be expected to return to market once 75% of the overall fund has been invested. At the 75% stage in a fund's life cycle, private equity firms reserve cash for follow-on investments and so need fresh cash for existing investments.