The fight between two influential government officials over the proposed $4.5 billion federal telecommunications network escalated yesterday when the powerful chairman of the House Government Operations Committee notified potential bidders that he wants the contract split up to increase competition.

Only two teams of companies are competing for the Federal Telecommunications System 2000 contract, one of the largest procurements in government history, and bids are due in 26 days.

Rep. Jack Brooks (D-Tex), chairman of the Committee on Government Operations, wrote potential bidders late yesterday afternoon "staking out a position that a two-vendor or more arrangement would increase competition among vendors," according to a source familiar with the letters.

Terence C. Golden, chief of the General Services Administration, which is handling the procurement, has adamantly supported a winner-take-all contract. Golden has argued that awarding the contract for the telecommunications network to more than one bidder would unnecessarily delay the system, cost the government money and cause turmoil in switching from the government's existing phone system to multiple vendors.

Brooks, in his letter to potential bidders on the contract, said he and Golden remained in fundamental disagreement over whether the contract should be awarded to a single vendor, but that GSA had made some concessions to clarify and improve the bidding process, agreeing to: Use outside participation on the Source Selection Board -- the government panel that will examine the bid.

Clarify the evaluation criteria.

Study in depth the government's long-term telecommunications requirements.

Clarify the national security/emergency preparedness requirements.

Hold a bidders' conference prior to receipt of the bids to answer questions and explain changes.

Golden also has agreed to select the winning vendor personally and to ensure that the government would not be locked into any contract for more than four years, according to one official familiar with the negotiations.

Brooks has expressed concern that the government would be locked into a contract with a monopoly supplier for 10 years.

Of the two teams still competing for the contract, one is led by American Telephone and Telegraph Co., the other by Bethesda-based Martin Marietta Corp., which has teamed up with MCI Communications Corp. of Washington.

A third consortium made up of U.S. Sprint Communications Co. and Electronic Data Systems Corp. withdrew last month when EDS backed out of the partnership. U.S. Sprint, which would like to re-enter the fray, could well have an opportunity to do so under the Brooks approach.

A.J. (Herb) Linnen, a spokesman for AT&T in Washington, said last night that "we are responding to the only RFP {request for proposal} that's out there. If the government decided it's in its best interest to award the contract to a number of vendors, we will respond to that. Right now we're driving toward that Aug. 31 deadline" laid out in the original GSA proposal.

Spokesmen for Martin Marietta and U.S. Sprint could not be reached for comment.

Brooks' office said the congressman would have no comment beyond the letter. Brooks is a 17-term congressman from Beaumont, Tex., whose committee oversees federal procurement.

Golden issued a statement saying, "We do have some differences with Government Operations, but we are actively working with Chairman Brooks and negotiations are ongoing.