Donald Rainey, a member of Intersouth Partners venture team since 2000 and the partner assigned to run its office in suburban Washington, D.C., is leaving the firm.

Intersouth said Rainey would depart Sept. 15. He is joining another venture, the name of which was not disclosed.

“He’s asked us not to disclose so he can announce it himself,” said Suzanne Cantando, a spokesperson for Intersouth.

Rainey came to Intersouth in 2000 from TotalSumParts, a Web development firm that he founded in Reston, Va.

No replacement was named. Intersouth has made numerous investments in the Washington, D.C. region.

“We consider the Baltimore and Washington, DC area to be an integral part of Intersouth’s investment strategy,” said Mitch Mumma, general partner with Intersouth Partners, in a statement. “We appreciate the contributions Don has made over the years as we’ve grown our investment footprint in the region, and we wish him the best in his new endeavors. We look forward to identifying exciting new companies in which to invest while providing continued support for our active portfolio of technology and life science companies in the region.”

Current members of Intersouth management will take over Rainey’s portfolio duties, Intersouth said.

Rainey is a former executive with IBM and Novell. He also was part of the management teams at and DaVinci Systems, which were sold to other firms. DaVinci Systems was based in the Triangle.

He was made a full partner in Intersouth in 2003.