Stifel Financial and Thomas Weisel Partners Group have entered into a definitive merger agreement. The deal is valued at more than $300m, which includes the outstanding shares and restricted stock units and warrants.

Thomas Weisel Partners (TWPG) will be merged into a subsidiary of Stifel and become a wholly-owned subsidiary of Stifel. The terms of the agreement, approved by the boards of both companies, call for each TWPG share to be exchanged for 0.1364 shares of Stifel Financial common stock.

Upon the completion of the merger, Thomas Weisel, founder of Thomas Weisel Partners Group and Ronald Kruszewski, CEO of Stifel, will serve as co-chairmen of the borad and Mr Kruszewski will remain president and CEO of Stifel Financial .

Mr Weisel said: “There is virtually no overlap in investment banking and less than a 10% overlap in research coverage. Our platform adds key growth sectors to Stifel’s investment banking business, particularly in technology, healthcare and energy. Stifel has one of the largest global wealth management groups with nearly $100bn in client assets, which is a great complement to the combined investment bank.”

Mr Kruszewski said: “Both Stifel and Thomas Weisel Partners have very strong, highly entrepreneurial associates, and both firms’ areas of expertise will be quite complementary. Together we expect to continue to grow the core businesses, expand our offerings and add depth to our focus sectors to increase our market share.”

The merger is subject to approval by Thomas Weisel Partners shareholders and customary regulatory approvals. The transaction is expected to close on or about June 30, 2010.