The Senate voted overwhelmingly yesterday to limit a potential conservative filibuster over legislation imposing sanctions on South Africa, but the bitter talkfest continued amid conflict over how tough the sanctions should be.

The 88-to-8 cloture vote was an indication of wide support for new measures against South Africa's apartheid policy of racial separation. At the least, the Senate is likely to approve a ban on new U.S. bank loans and nuclear technology exports and curbs on computer sales to the Pretoria regime.

The House has already passed those measures as part of a tougher bill.

The proposed Senate measure would also allow a ban on all new U.S. investment in South Africa and on the importation of gold South African krugerrand coins if the white government does not improve its racial policies within 18 months. It would require most U.S. firms to observe the Sullivan principles requiring desegregation within their facilities, and promotions and pay raises for blacks.

The filibuster threat, led by Sen. Jesse Helms (R-N.C.), was reportedly aimed not at killing the sanctions -- which is not considered possible given the mood of Congress -- but at blocking any further toughening of the bill.

A cloture vote limits the 100 senators to one hour of debate each and requires that any amendments be germane to the bill.

Sen. Alan Cranston (D-Calif.), one of several senators planning to offer stiffening amendments, made an unusual personal attack on Helms before the cloture vote.

"If the senator from North Carolina had been in the Senate 122 years ago, he probably would have opposed emancipation because it would throw 4 million slaves out of work," Cranston said. "Incredible! If Russia had been communist 122 years ago, [Helms] would probably have accused the abolitionists of being Soviet agents."

Helms responded by saying Cranston had called him a racist, and that the charge was "a bit of a violation of tradition."

Senate leaders worked to negotiate an agreement limiting the time for debate on the motion to take up the bill, which otherwise could take 100 hours under rules governing the cloture vote. They said they hoped to proceed to substantive work today.