WASHINGTON (AP) -- Freshman Democratic Sen. Jim Webb of Virginia announced Wednesday he will retire when his term ends next year, deepening the challenge to his party as it struggles to maintain a majority in the 2012 elections.
In an e-mail announcement, Webb said that after much thought and consideration, he had decided to return to the private sector. He offered no additional details about his plans but said he intends to remain involved in issues that affect the future and well-being of the country.
Webb, a former Navy secretary, was elected to the Senate in an upset in 2006, ousting Republican Sen. George Allen by about 9,000 votes.
Allen, the former governor whose campaign was riddled with embarrassments, is attempting a comeback in 2012, although he faces primary opposition. He did not immediately respond Wednesday to a request for comment on Webb's plans.
Democrats, with a 53-47 majority, must defend 23 Senate seats next year, including two held by independents. Many are in swing states where Republicans hope to mount strong challenges.
By contrast, only 10 GOP-held seats will be on the ballot.
The National Republican Senatorial Committee said Webb's decision makes Virginia an "even stronger pickup opportunity for Republicans in 2012." But the chairwoman of the Democratic Senatorial Campaign Committee, Sen. Patty Murray of Washington, said the party would field a strong candidate.
Since taking office, Webb has focused much of his energy on international issues.
"Among other contributions, we have given our post- 9/11 veterans the best GI Bill since World War II," he said in his statement. "We have taken the lead in reforming our criminal justice system. We have led the way toward stronger relations in East and Southeast Asia."
Earlier in his career, Webb was a combat Marine in Vietnam, a lawyer, congressional aide and a published author. His appointment as Navy secretary came from President Ronald Reagan, a Republican. But when the Naval Academy graduate made his only run for public office, it was as a Democrat.
Webb is the fourth senator to announce plans to retire. The others are Sen. Kent Conrad, D-N.D., Sen. Kay Bailey Hutchison, R-Texas, and Sen. Joseph Lieberman, I-Conn.
Associated Press Writer Michael Felberbaum in Richmond, Va., contributed to this report.