China's new state investment firm on Sunday said it plans to make a $3 billion investment in the Blackstone Group, one of the most prominent and powerful U.S. private equity firms.

China's soon-to-be-established foreign exchange investment company would make the investment in the form of nonvoting common units of Blackstone, a firm that has been at the forefront of a global boom in mergers and acquisitions.

China announced in March it was setting up a vehicle to help diversify part of its $1.202 trillion of foreign exchange reserves, the world's largest, to improve returns and diversify risk.

State media have said the new agency could manage up to $200 billion, although some Chinese economists have called for twice that amount to be at its disposal.