The National Venture Capital Association (NVCA), the US trade body of the private equity industry, has entered the fray over pressure for pension funds to disclose performance data.

The association has filed a complaint with a Californian court. The amicus brief, which is a document declaring it a "friend of the court", is to help a state pension fund defend itself from legal attempts to make it reveal details of fund performance. The NVCA says it fears investors forced to reveal their fund performance will be banned by private equity firms from future investments.