A congressman has asked the Legal Services Corp. to explain why its chief counsel was disciplined last month after he warned corporation President Donald P. Bogard that several grants he was about to issue would violate federal procedures.

Bogard ignored the warning from Robert D. Frank, a former state judge from Tulsa who had been at the corporation for less than five months, and awarded the contracts Sept. 30, the last day of the fiscal year. Congress had ordered the corporation to spend its $275 million budget before the fiscal year ended.

Three of the grants, totaling $1 million, were made to conservative groups without competitive bidding. Rep. Barney Frank (D-Mass.) -- no relation to the LSC counsel -- is also investigating whether the three groups were eligible for the funds.

James Streeter, a spokesman for the corporation, confirmed yesterday that Frank resigned last week, effective Dec. 31, after being placed on "administrative leave" by Bogard, who had hired him.

Frank declined to discuss his resignation, but Rep. Frank accused Bogard of disciplining the attorney because he had questioned the grants.

"It appears as if Legal Services Counsel Frank may be the unfortunate victim of a Legal Services policy that punishes those who are critical of President Bogard's agenda even if it means the abrogation of statutory requirement," Rep. Frank said. "I am disappointed at this latest politicization of the Legal Services Corp."

Rep. Frank has been a frequent critic of Bogard and the Reagan administration, which has tried repeatedly to persuade Congress to eliminate the quasi-private corporation. The corporation was created to provide free legal assistance to the poor, but the administration contends that it has overstepped its bounds and become an advocate for liberal causes.

Streeter said Bogard would not comment on why he had disciplined Frank, but said that it was not related to Frank's warning.

In a memo Sept. 5, Frank told Bogard that the corporation had to publish a public notice and notify state and local officials 30 days before awarding any contract that "will result in the direct delivery of legal services to eligible clients."

Streeter said Frank's opinion had been strongly contested by corporation officials who administer grant programs. They claimed that the 30-day notice was not required. The corporation has not published a 30-day notice in such cases since 1977, Streeter said.

Streeter said Bogard decided after he had awarded the grants that Frank's legal opinion might be correct, so the corporation published a public notice about the grants that already had been awarded, including the three that Rep. Frank is investigating.

"He [Bogard] told me that he now agrees with the memo," Streeter said.

The three contracts Rep. Frank has questioned were awarded to the Constitutional Law Center in Cumberland, Va.; the Oakland Urban Legal Foundation and the National Center for the Medically Handicapped in Indianapolis.

"These groups are pretty far out," Rep. Frank said when he learned of the contracts. The Indianapolis grant might help poor people, he added, but he described the other two as "simply ideological."

Streeter said yesterday that it was wrong to identify the groups as conservative and defended them as valid grant recipients.