Prosperity Bank has completed the acquisition of American State Bank which operated thirty-seven banking offices in eighteen counties across West Texas.

As of 31 March 2012, American State Bank reported total assets of $3.16bn, total loans of $1.24bn and total deposits of $2.51bn.

American State Bank chairman and CEO W. R. Collier will become a director of Prosperity Bancshares and will serve as its senior chairman of West Texas Area.

Collier said, "This merger provides our customers with significantly expanded banking opportunities while maintaining our community bank approach to doing business."

American State Bank president Michael Epps will serve as chairman of West Texas Area and will manage all West Texas locations.

Sandler O’Neill + Partners acted as financial advisor to American State Bank in the transaction while Keefe, Bruyette & Woods was the financial advisor counsel to Prosperity.

Prosperity chairman and CEO David Zalman said, "Upon the completion of our operational integration, the customers of American State Bank will be able to use any of our locations across the state of Texas."