Sen. Alan Cranston actively solicited contributions from savings and loan owner Charles H. Keating Jr. at times when Keating wanted help with federal banking regulators, the Senate Ethics Committee's chief counsel charged Friday.

"On approximately four separate occasions, Senator Cranston accepted or solicited several hundred thousand dollars from Mr. Keating" for his campaigns or voter registration drives to which he was closely associated, said counsel Robert S. Bennett.Each of those contributions was linked "by time and circumstances with a request by Mr. Keating" for action with federal bank regulators, Bennett said.

Bennett outlined the case against Cranston on the second day of the committee's hearings into the links between five senators and Keating, whose Lincoln Savings and Loan failed at an estimated cost to taxpayers of $2 billion.

But before he began, Cranston's lawyer asked that one of the six committee members, Sen. Jesse Helms, be barred from judging the California Democrat.

Helms, speaking under oath, stoutly denied the charge by Cranston attorney William W. Taylor III that he had already made up his mind in the case.

Taylor's request reflected the political tensions involved as the Senate panel sits in judgment on the five prominent lawmakers. Three of the five, Sens. Donald Riegle of Michigan, Dennis DeConcini, D-Ariz., and John McCain, R-Ariz., were present at Friday's hearing. Sen. John Glenn, D-Ohio, and Cranston, who is ill with prostate cancer, were not.

Bennett said Keating made a $100,000 contribution to a voter registration project associated with Cranston on March 3, 1987, less than a month before Cranston and other senators met with top bank regulator Edwin Gray on behalf of Keating.

That fall, Keating gave another $250,000, and six days later Cranston called Gray's successor, Danny Wall. Bennett cited a memo to Cranston from one of his fund-raisers, who said Wall's appointment was "good news" for Keating. The same memo said, "You should ask Keating for $250,000."

Bennett depicted Cranston as aggressively seeking contributions from Keating.

Bennett irritated Ethics Chairman Howell Heflin, who suggested Bennett was singling out Cranston when many senators request contributions. At one point, when Bennett insisted he was being evenhanded, Heflin interjected, "Selectively."