The top liaison to Capitol Hill during the presidential campaign of Sen. John Kerry (D-Mass.) has signed on as a partner with an up-and-coming lobbying firm run by a pair of GOP strategists who have deep connections to the White House and Senate Republican leadership.

David Castagnetti, who headed Congressional relations for the Kerry-Edwards campaign team, has been named a partner at the firm now known as Mehlman, Vogel, Castagnetti, Inc., providing the fast-growing lobbying firm with its first taste of bipartisanship.

At the firm, Castagnetti joins Bruce Mehlman, a former assistant secretary of Commerce for technology policy in the Bush administration who is perhaps better known as the brother of Ken Mehlman — the campaign manager for the Bush-Cheney re-election effort and incoming chairman of the Republican National Committee.

Also at the firm is Alex Vogel, who served as chief counsel to Senate Majority Leader Bill Frist (R-Tenn.) in 2003 and remains his top political lawyer.

Castagnetti’s “stellar reputation for integrity and effectiveness, combined with the incredible depth of his relationships in Congress, will expand our ability to help our clients win in Washington,” Mehlman said today in a statement.

Castagnetti previously served as chief of staff and top adviser to Sen. Max Baucus (D-Mont.), the ranking member of the Senate Finance Committee, as well as then-Rep. and current Transportation Secretary Norm Mineta (D-Calif.). He is expected to help with the firm’s technology and trade practice.

The firm, which debuted in May 2004, now boasts 17 clients, including Nextel and IBM. On Dec. 1, Covington & Burling signed up Mehlman, Vogel to work on IBM’s effort to sell off its personal computer division to China’s Lenovo Group Ltd., according to reports filed with the Secretary of the Senate. The $1.75 billion cash-and-stock deal was publicly unveiled six days later.

In its first weeks of operation, the firm brought in $270,000 in revenue, according to mid-year 2004 lobbying reports.

Vogel, who also served as Frist’s counsel while he chaired the National Republican Senatorial Committee, handled complicated legal issues for Frist, such as a settlement on asbestos claims — a background that helped the firm land such clients as U.S. Chamber of Commerce’s Institute for Legal Reform and Owens Corning.