(Reuters) Former Republican Senator Judd Gregg is stepping down from his post as chief executive of the Securities Industry and Financial Markets Association (Sifma) after less than a year in the position.

The board of Sifma, a major Wall Street trade group, appointed its current president, Kenneth E. Bentsen Jr., as Gregg's replacement, SIFMA said in a statement on Thursday.

In that role, Bentsen will serve as both president and chief executive.

Gregg will continue serving as a senior adviser to the group, which has played an important role in lobbying for changes to the 2010 Dodd-Frank Wall Street reform law and in mounting legal challenges.

In Sifma's statement, Gregg said he was stepping down due to the stresses surrounding his travel schedule.

"My decision to step down as CEO of Sifma does not in any way diminish my commitment to and involvement in promoting the critical role a vibrant capital markets system plays in helping Americans succeed and Main Street prosper, but only reflects my personal need to spend less time commuting to Washington from New Hampshire and slowing a hectic schedule," Gregg said.

Before joining Sifma, Gregg held numerous government roles.

In addition to three terms as a U.S. senator, he served two terms as governor of New Hampshire and four as a congressman representing the Granite State. At one point, he was a nominee to serve as U.S. secretary of Commerce under President Barack Obama until he withdrew his name, citing differences over policy matters.

While in the Senate, he served on the Senate Banking Committee during the drafting of the 2010 Dodd-Frank Wall Street reform law.

Gregg's sudden departure as CEO of Sifma comes roughly seven months since he was appointed to the post in May.

Before Gregg's arrival, Bentsen, a veteran lobbyist well-versed in regulatory issues facing financial markets, had been serving as the group's president and acting chief executive.

Gregg's appointment marked the first time the group had decided to separate the role of chief executive and president.