Incoming budget director Thomas B. (Bert) Lance got a warm reception from senators at his confirmation hearing yesterday, but he made one concession that may bring cries of pain from his new colleagues at the Office of Management and Budget.

Lance, who seems assured of a favorable vote from the Senate Government Operations Committee today, promised Sen. John H. Glenn Jr. (D-Ohio) he would support Glenn's hill to give Congress access to department and agency budget requests at the same time those requests go to OMB.

A budget professional on Capitol Hill called that a "drastic change" in past procedures, and Lance later conceded to reporters that "I did not understant that was the intent of his legislation."

The Atlanta banker, who served as director of the highway department and architect of government reorganization when President-elect Jimmy Carter was governor of Georgia, made a big hit with Democratic senators who four years ago found themselves in angry confrontations with the Nixon administration's OMB director, Roy Ash, over exactly the sort of information Lance volunteered to give them yesterday.

Liberal and conservative Democrats and the lone Republican present Sen. Richard Lugar of Indiana, praised Lance's cooperation and his promise to work for a balanced budget and reduction of the paperwork burden that government imposes on business and private citizens.

Other Republican senators, absent yesterday, requested a return appearance today by Lance, but there was no sign of opposition to his confirmation.

Glenn had no difficulty getting Lance to agree to support his bill requiring concurrent submission of agency budget requests to Congress.

"Yes, senator," Lance said, "I believe it's important . . . I'm not fully informed on the kind of information that may be there, but certainly as far as I'm concerned, in order for us to have the best possible information to make decisions on, you ought to have access to that, the same as OMB does . . . We're all in this thing together."

OMB has traditionally taken the view that budget requests from the agencies should remain within the executive branch, and that agency officials should testify only in support of the amounts finally recommended by the President. By gaining access to the original agency requests, Congress and special interest groups can more easily make a case for increasing the President's budget.

Questioned later about his statement, Lance told reporters he wanted to cooperate with Congress "but not limit the role of OMB," and indicated he thought Congress should have access to the departmental requests after, but not before, the President's budget is submitted.