State-backed QNB said the deal must still be approved by the UMB's board and regulators.

Financial details weren't provided.

Qatar's sovereign wealth fund, the Qatar Investment Authority, controls QNB through a 50 percent stake.

The deal comes a day after another government-owned Gulf investor, Abu Dhabi's Aabar Investments, agreed to raise its stake in Italian lender UniCredit to 6.5 percent from about 5 percent now.