Six real estate firms operating in Montgomery County that were convicted last year of price-fixing have been denied a chance to plea bargain in their fight to retain their brokers licenses.

The realtors had asked the Maryland Real Estate Commission to hold a special meeting next week so they could make an arrangement enabling them to keep their licenses. Their lawyers contended such an understanding was necessary for the firms to settle class actions against them.

As reported previously, the companies have offered a non-cash settlement to home-buyers who claim damages for having had to pay 7 instead of 6 percent commission in 1974. It would be a kind of "scrip" allowing them to purchase a house in the future at 5 percent commission. The "scrip" would also be negotiable in the sense that if the owner declined to use it, he or she could try to sell it to another homebuyer.

Were the companies not allowed to sell houses, they could not honor the terms of the proposed settlement, attorneys argued.

The convicted companies were Colquit-Carruthers Inc., Jack Foley Realty Inc., Bogley and Co., Shick and Pepe Realty Co., Shannon and Luchs Co. and Robert T. Gruen Inc.

At its regular meeting this week, the real estate commission unanimously declined to hold a special session. It also rejected a request by the companies to cancel its scheduled hearing in September when it will consider disciplinary proceedings, as required by law in the wake of the realtors' criminal convictions.

"What do you think the public is going to think if we give these people special consideration?" Commissioner John J. Moran Jr. said at the meeting.