An auditor from a national accounting firm hired by the University of the District of Columbia trustees told a D.C. City Council committee yesterday that former president Robert L. Green routinely replenished his presidential discretionary account with other university funds and treated it "like a petty cash fund."

A. William Mann of Coopers & Lybrand, the firm hired by the trustees last July to audit Green's representation fund and also the university's larger postsecondary education account, said his firm has found more expenditures by Green than have been previously reported, including $1,450 for a trip he and his wife took to Rod Laver's tennis resort in Florida and $2,287 in membership fees for his wife to join the Bethesda Health and Racquet Club. Those expenditures were from the $15,000 discretionary account that, Mann said, Green's spending had exceeded in fiscal 1985 by more than $5,000.

Mann told members of the council's Education Committee that the representation fund, which was established to cover the president's expenses related to his official duties, "was treated like a reimbursable fund -- like a petty cash fund."

At a seven-hour hearing, the second in a series of committee hearings on the financial practices at UDC, Committee Chairman Hilda Mason (Statehood-At-Large) and committee member Betty Ann Kane (D-At-Large) questioned why the trustees had not asked outside auditors to investigate allegations of financial improprieties by Green after Mason told trustees of the allegations last February.

Frank Ross, a senior partner with the accounting firm of Peat, Marwick and Mitchell, which prepares the university's annual financial report, said the trustees board had never suggested to his auditors that there were financial problems at the university. He said his firm received approximately $45,000 from the trustees to prepare an external audit that is not as comprehensive as audits currently being performed by Coopers & Lybrand and D.C. Auditor Otis H. Troupe.

Green resigned under pressure on Aug. 23 after disclosures that he had spent thousands of dollars of university funds for travel, consulting and personal items.

Kane also questioned Coopers & Lybrand's methods of reviewing the president's representation fund, which relied on Green's explanation of some expenditures that were not supported by receipts or other documentation.

"You were satisfied with Dr. Green's verbal explanation?" Kane asked. "Did you really believe that in dealing with public money that was adequate information?"

Kane said a report on the representation fund released by Coopers & Lybrand in July could have influenced the board's decision to buy out one of the three years remaining on Green's $74,900-a-year contract and also led to "unfair" criticisms of Troupe, who issued a harsher report on Green's expenditures.

For the second week in a row, the Education Committee members posed tough questions for the trustees, seeking detailed explanations of board practices that could have allowed Green's spending to go unchecked. Mason introduced a university memorandum showing that the board had approved a measure allowing the internal auditor to report directly to Green and not to the trustees. This contradicted testimony last week by Daniel I. Fivel, the chairman of the board's finance and audit committee.

Mason criticized Fivel for saying that the trustees were ill-equipped to monitor all of the university's finances because of a lack of staff.

"If the job is too big for you, then step down," Mason said to Fivel during a heated exchange.

Samuel Halsey, the university's internal auditor, testified late last night that Green once "chewed" him out for briefing members of the trustees' finance and audit committee and later instructed him to report directly to the president's office. He said that decision was "a major factor" contributing to financial abuses by Green.

"The internal auditor has to have the appearance of independence as well as de facto independence," Halsey said. "I have to be independent."

Mason and council members Kane and Carol Schwartz (R-At Large) pressed N. Joyce Payne, the new chairman of the UDC board of trustees, on whether the trustees had ever taken action in private session that should have been conducted in public. Under District law, the board is required to meet in private only when confidential personnel matters are being reviewed.