An acid exchange occurred yesterday in the Senate Foreign Relations Committee as one senator told another, "If you railroad me, Mr. Chairman, you'll regret it" and a third senator said the panel was laying its internal squabbles before the public.

At issue was an attempt by Sen. Jesse Helms (R-N.C.) to block action on an ambassadorial nomination pending almost all year.

In the end, the committee voted 11 to 3 to send to the Senate floor the nomination of Foreign Service veteran Richard Noyes Viets as ambassador to Portugal, with a recommendation that he be confirmed.

Helms has long objected to the nomination of Viets, who has served as ambassador to Jordan and Tanzania.

His grounds include grievances filed against Viets by three junior diplomats and allegations that he may not have paid state and district taxes in certain U.S. jurisdictions.

Helms complained that the State Department is engaged in a "cover-up" because it has declined, on privacy grounds, to give him access to Viets' full personnel files.

"Mr. Viets is a totally unsatisfactory diplomat and the State Department is withholding information," Helms said.

Committee Chairman Claiborne Pell (D-R.I.) said he is sure that the questions raised by committee members have had a "beneficial impact" on Viets and that in the future he will be "much more sensitive and careful in dealing with administrative and personnel matters."

Noting that the Portugal post has been vacant for a year, Pell said further delay "could have a negative impact on our crucial political, cultural and security interests in that country."

When Pell said that it was important to "get on with the nation's business," Helms replied: "Bull!"

Under the rules, Senate committees were required to end morning business meetings by 11 a.m. The clock was running and senators accused Helms of filibustering to prevent action before the deadline.

Helms' attempt to table the nomination was defeated 11 to 5 and he launched into a speech. Pell attempted to cut him off. Helms insisted he had the floor and could not be stopped.

"You cannot take the floor away from me," Helms told Pell. "If you railroad me, Mr. Chairman, you'll regret it."

Pell held his ground.

"It's been more than a year; Mr. Viets deserves a vote," the chairman said.

"No, he doesn't," Helms replied.

Sen. Richard G. Lugar (R-Ind.), the former committee chairman, attempted to intervene.

"You're no longer the ranking member," said Helms, who now holds that post.

Lugar replied that he is still a senator and a committee member and has rights under the rules.

Helms pleaded for other senators to leave the room with him, to deny the panel the necessary quorum to do business.

No one budged. But Sen. Frank H. Murkowski (R-Alaska) asked for a brief recess. "To attempt to do our internal laundry in public is uncomfortable and embarrassing," he said. The time was 10:59 a.m. and Sen. Brock Adams (D-Wash.) moved the nomination be approved.

Pell ruled that the vote could continue because it had begun before the 11 a.m. deadline.

Helms walked out. The committee, at 11:03 a.m., finished its vote.