A former top federal savings and loan regulator testified yesterday that the actions of five senators who intervened on behalf of thrift operator Charles H. Keating Jr. in 1987 had no effect on the agency's treatment of Keating's now-defunct Lincoln Savings and Loan.

Rosemary Stewart, who was then the head enforcement lawyer for the Federal Home Loan Bank Board, told the Senate Select Committee on Ethics she was under no political pressure when she negotiated an agreement with Keating's lawyer in 1988 to resolve a Lincoln dispute. That agreement with regulators from the agency's San Francisco office has been criticized because it disregarded results of an earlier San Francisco examination of Lincoln's loans and investments.

Stewart also said she was not affected by a call an aide to Sen. Alan Cranston (D-Calif.) made to the agency during the 1988 negotiations. This contradicted the statement of William Black, one of the San Francisco regulators, who contended the call from Carolyn Jordan was a factor in delaying the closing of Lincoln for another year. The collapse of Keating's thrift is expected to cost taxpayers nearly $2 billion.

Stewart was called as a Cranston witness as the so-called "Keating Five" hearings reopened after a holiday recess. Cranston and Sens. Dennis DeConcini (D-Ariz.), John Glenn (D-Ohio), John McCain (R-Ariz.) and Donald W. Riegle Jr. (D-Mich.) have all said their actions on Keating's behalf were unrelated to the $1.3 million he raised for their political campaigns and personal causes.

The five senators are scheduled to face examination by their lawyers and committee special counsel Robert S. Bennett, starting Friday with McCain.

Sen. Warren B. Rudman (R-N.H.), the committee's vice chairman, expressed frustration at the pace of yesterday's hearing. He told Cranston attorney William Taylor III that he was "deeply concerned" about the relevance of much of Taylor's two hours of questioning, most of which concerned Stewart's knowledge of the views of Washington regulators toward the quarrel between Lincoln and San Francisco, rather than the actions of the senators.

Stewart said she got involved in the Lincoln case in May 1987. A month earlier all the senators except Riegle met with then-agency chairman Edwin Gray. All five met a week later with San Francisco regulators.

Stewart and other top bank board officials concluded in May that the San Francisco regulators had not produced enough evidence to warrant placing Lincoln under government control.

Stewart agreed with Bennett that criminal referrals the San Francisco regulators mentioned in the second meeting with the senators raised "major league red flags." But she said they were not relevant to a decision on taking Lincoln away from its management.