Westwind Partners today agreed to be purchased by San Francisco-based investment bank Thomas Weisel Partners Group, Inc. in a cash-and-stock deal valued at about $150 million.

The agreement comes on the heels of last week’s purchase of Orion Financial Inc. by Macquarie Group Ltd.

Thomas Weisel will acquire Westwind for US$146.7 million based on the closing share price on September 28, consisting of US$45 million in cash and 7.009 million shares of Thomas Weisel common stock. Closing of the transaction is expected to occur in January 2008 and is subject to customary closing conditions, including regulatory approvals and approval by Thomas Weisel shareholders. The firm expects Westwind to add between US$100 million and US$110 million to its revenues in 2008.

Westwind, founded in 2002 and headquartered in Toronto, has offices in Calgary, Montreal and London with approximately 100 employees.

The clientele for Westwind’s investment banking and brokerage arms consists mainly of mid-to-small cap plays in the energy and mining sectors.

Its investment banking team has executed over $17 billion in capital raising transactions during the last five years and has been lead or co-lead manager of over 140 transactions. With over 20 senior trading and sales professionals and 14 publishing analysts, Westwind’s brokerage group covers over 120 companies in six sectors.

“I am pleased to announce the acquisition of Westwind and am looking forward to Lionel Conacher, Westwind’s CEO and president, joining us as president of Thomas Weisel Partners,” said Thomas Weisel, CEO and chairman, in a news release. “This acquisition will give us access to the energy and mining sectors which are key verticals to expanding internationally and highly complementary to our existing coverage universe.”

“Culturally, the Westwind team is very much like our own,” Weisel continued, “they are principled, entrepreneurial, passionate about helping growing companies access the capital markets, and dedicated to providing superior independent advice.”

“My partners and I are looking forward to joining Thomas Weisel Partners and we are very excited by the prospect of leveraging the TWP brand in Canada and abroad,” said Conacher.