The Chinese government is to use $3bn of its vast foreign exchange reserves to buy a 9.9 per cent stake in Blackstone, the US buy-out fund, in an unprecedented move that underlines Beijing’s desire to tap into the private equity boom.

The investment will coincide with Blackstone’s landmark $40bn stock market listing, expected in the next few months, and will allow the private equity group to nearly double its original target of raising $4bn.