Mizuho Financial Group is forging further into U.S. investment banking through a deal to buy Greenhill as it seeks to accelerate growth.

The Japanese banking giant agreed to buy Greenhill for $15 a share in an all-cash transaction, which values the firm at $550 million (¥76 billion) including debt, the firms said Monday in a statement. The lender will retain Greenhill’s leaders, including CEO Scott Bok, who will be chairman of mergers, acquisitions and restructuring.

Mizuho joins its Japanese rivals to expand investment banking tie-ups in the U.S. — though goes a step further in making an acquisition. Sumitomo Mitsui Financial Group last month said it will expand a tie-up with Jefferies Financial Group to boost U.S. capital markets and M&A advisory businesses. Japan’s largest bank, Mitsubishi UFJ Financial Group, has a more than decade-old alliance with Morgan Stanley, a deal struck in the heat of the 2008 financial crisis.