The Senate Foreign Relations Committee on a 10 to 9 party-line vote Wednesday approved and sent to the Senate floor legislation imposing harsh economic sanctions against white-dominated South Africa. The vote took place after Sen. Alan Cranston, D-Calif., modified the bill to remove a provision that could have caused foreign oil companies to lose American oil leases if they acted to undercut the sanctions legislation. Sen. Jesse Helms, R-N.C., said Cranston was moving to change a bill Helms called a "turkey." The committee's 10 Democrats voted for the measure and the nine Republicans against it.