PIERRE, S.D. (AP) _ Former South Dakota Gov. Mike Rounds says he will run for the U.S. Senate in 2014. Rounds made the announcement in an event held in Pierre. He planned to hold other events later Thursday in Rapid City and Pierre. The former Republican governor earlier formed a committee to explore a run for the U.S. Senate seat now held by Democrat Tim Johnson, who has not yet announced whether he will seek re-election to a fourth term. Rounds was a state senator from 1991 to 2001 before being serving two terms as governor from 2003 to 2011. After leaving office in early 2011, Rounds returned as president and CEO of an insurance and real estate business that is based in Pierre. AP-WF-11-29-12 1438GMT<