U.S. Senator Lisa Murkowski said on Thursday she will unveil a bill next week that would reverse the 40-year-old ban on U.S. oil exports. Murkowski, the Republican chairwoman of the Senate Energy and Natural Resources Committee, said she would unveil the bill on Tuesday, although it was uncertain when the measure would get a vote in her committee. Murkowski has been one of the biggest supporters of reversing the ban Congress passed in 1975 after the Arab oil embargo led to fears of energy shortages. (Reporting by Timothy Gardner ; Editing by Will Dunham )