TULSA, Okla. -- Following the lead of Hertz and Avis, four more national car rental units have stopped paying travel agency commissions on corporate and government accounts under contract.

Dollar Rent A Car, Thrifty Car Rental, Alamo Rent-A-Car, National Car Rental and Budget Rent A Car will no longer pay commissions on U.S. and Canadian car rentals for corporate and government accounts operating under negotiated contracts.

The changes in policy will not affect commissions paid on leisure, association and non-negotiated corporate and government rentals.

"After considerable evaluation, Dollar feels this cost-reduction program is necessary to remain competitive in the marketplace," said Fred J. Fleischner, vice president of sales and marketing for Dollar.