Aberdeen Asset Management, the US$198 billion U.K.-based traditional and alternative asset manager, has agreed to acquire Credit Suisse’s $58 billion long-only asset management arm.

Credit Suisse sold the unit for approximately 240 million shares in Aberdeen, which were valued at $363 million as of yesterday. The closing of the deal is on June 30, 2009, subject to shareholder and regulatory approval.

Aberdeen’s largest hedge fund shareholder, Martin Hughes, chief executive of Toscafund, said, “Toscafund has already confirmed its support for this transformational acquisition, which has been made possible by the excellent operating platform offered by Aberdeen.”