San Francisco-based investment bank Thomas Weisel Partners Group, Inc. says it has completed the acquisition of Toronto-based Westwind Partners, a full service, institutionally oriented, investment bank focused on the energy and mining sectors.

The deal was first announced in October 2007.

“I am pleased to announce the completion of our acquisition of Westwind and the appointment of Lionel Conacher, formerly Westwind’s CEO and president, as president of Thomas Weisel Partners,” said Thomas Weisel, CEO and chairman, in a release.

“The completion of this acquisition establishes Thomas Weisel Partners’ presence in the energy and mining sectors, expands our presence in Canada and Europe and represents a significant milestone in the building of the premier, global growth-focused investment bank,” Weisel added.

“We will begin immediately leveraging the TWP brand in Canada and abroad in order to capitalize on the synergies that we expect from the combination of our firms,” said Conacher.

In connection with the integration of Westwind, Thomas Weisel Partners says it will more closely align the compensation practices of the two firms with one another and with industry practice by discontinuing the payment of mid-year retention bonuses.

TWP will accelerate the payment of its 2008 mid-year retention bonuses, which were historically established at year end and paid in the following July, so that they become part of 2007 year-end bonuses, which are paid in February.

TWP says it will record a one-time compensation expense in the fourth quarter of 2007 related to this change in compensation practice, as well as a one-time expense related to certain acquisition-related severance payments. The aggregate one-time charge associated with these matters is expected to total approximately US$23.2 million and to reduce GAAP diluted earnings per share by approximately 50¢ per share for 2007.

TWP also announced selected preliminary fourth quarter 2007 financial results and estimates of the 2007 compensation ratio. In the fourth quarter of 2007, TWP estimates that its brokerage revenues increased by approximately US$4 million to US$34 million and its investment banking revenues increased by approximately US$6 million to US$32 million, in each case compared to the third quarter of 2007.

In addition, TWP currently estimates that, as a percentage of net revenue, compensation and benefits expense will be approximately 59% for 2007. TWP estimates that the one-time compensation expenses described above will increase the 2007 compensation ratio by approximately 9%.