OLYMPIA — U.S. Rep. Norm Dicks is likely to succeed the late Rep. John Murtha as chairman of the House subcommittee that oversees Pentagon spending. Murtha died Monday at age 77 after suffering complications from gallbladder surgery. The Pennsylvania Democrat was head of the House Appropriations defense subcommittee since 1989. Dicks, 69, a Democrat from Belfair, has sat on the committee since 1979. George Behan, Dicks’ chief of staff, said Monday that there’s no timeframe on when the change could take place, but that it would likely happen soon. He says the Appropriations Committee would have to agree to it, as would the House Democratic caucus. Dicks would have to give up his post leading an environmental spending panel, but would remain on the committee.