The terms call for one Bank United share to be converted into 1.3 shares of Washington Mutual's common stock at the Feb. 7 closing price of $50.84. Washington Mutual also has acquired more than 90% of Houston-based Bank United's preferred stock, Series A and Series B.

Bank United is a subsidiary of Bank United Corp and Texas' largest bank. It has $18.3 billion in assets, $8.7 billion in deposits and $846 million in stockholder's equity. The bank maintains 157 branches in Texas, 66 of which are located in Houston. It also has 23 regional offices in 16 states for its middle market commercial lending practice and 14 SBA lending offices in 10 states. The lender originates mortgage loans in 11 states, boasting a nationwide mortgage servicing business with 310,000 customers.

Washington Mutual Inc., which services consumers and small to mid-size businesses, has more than 2,000 offices in the US. It provides consumer banking, mortgage lending, commercial banking, consumer finance and financial services. This week Washington Mutual also has acquired residential mortgage banking business, The PNC Financial Services Group Inc.