U.S. Sen. Jay Rockefeller will not seek a sixth term representing West Virginia.

The 75-year-old Democrat has recently sparred with the state's mining industry over the future of coal, and he has supported President Barack Obama, who is deeply unpopular in West Virginia.

Rockefeller tells The Associated Press that public service has dominated his life for a half-century. He said he plans to retire in 2014 to devote more time to his family and vowed to remain a West Virginian.

Friday's announcement is sure to set off a scramble for the seat. Republican U.S. Rep. Shelley Moore Capito already has said she will seek it in 2014.

Rockefeller arrived in the state as an anti-poverty worker in 1964. His subsequent political career has also included two terms as governor.