Towing is tough.

Granted, it's no fun to return to your car and find that it's missing.

But tow-truck owners and operators say they are also having a tough time making it in an increasingly competitive industry, even in a city where legal parking spots are scarce.

It's hardly worth dealing with greasy wheels and angry car-owners, they said, when bidding matches slash profits to a minimum.

"Sometimes it's unpleasant, but you've got to do what you've got to do," said Robert A. Gatta, one of the owners of Cambridge Towing. "It's not a very fun business."

In order to be awarded contracts to tow cars from Cambridge public streets, towing companies undergo a competitive bidding process, city officials said. The Cambridge Parking Office handles the bidding process and awards the contracts to the three lowest bidding companies.

Pat's Towing, Phil's Towing and Cambridge Towing are the companies designated for the three-year period that began on April 1, 1992.

The process was so competitive this year that last year's average towing price of $32.50 dropped to $24.50 for two of those companies and $18.85 for the other, said Bernie A. Flynn, the assistant director of parking.

Flynn said police keep a rotating list of companies for those cars illegally parked, compounded and abandoned. As soon as the police ticket a car, the next company on the list is called to do the tow, Flynn said.

The companies are also required to take turns providing eight tow trucks to clear certain areas for street cleaning.

Before getting the chance to bid, the companies must meet other qualifications, including a requirement that the garage has to be within one mile of the city border.

Two of the companies that were awarded the contract, Pat's and Cambridge Towing, have recently moved to Somerville, just past the Cambridge city limits. Phil's Towing is near Fresh Pond in Cambridge.

Flynn said increasing land values in Cambridge make it economically unreasonable for towing companies to stay in the city.

Flynn said complaints about towing companies are "surprisingly very few," and most have to do with the "rudeness" of the towing operators.

"If we see a pattern, we'll discontinue the contracts. But like I've said, we've only had very few [complaints]," Flynn said.