Unions representing employes at Texas International Airlines yesterday accused the company of trying to start a cut-rate shuttle service, New York Air, by cutting their members out of jobs.

The new air service between Washington National and New York's La Guardia Airport is scheduled to take off Sunday.

But representatives of the Association of Flight Attendants, the Airline Pilots Association, the International Association of Machinists and the Teamsters said yesterday that they will protest the startup through "informational picketing" Sunday at the two airports.

The unions are charging that New York Air is a "runaway shop" -- an appellation usually reserved for northern firms fleeing south to get away from organized labor.

New York Air, however, is a wholly owned subsidiary of the Texas Air Corp., a New York-based holding company formed by the Houston-based Texas International Airlines.

The unions say New York Air is trying to get off the ground without union help.

"New York Air is the result of corporate maneuvering which attempts to leave the Texas International flight attendants out in the cold, while a new nonunion airline is set up," said Susan Bianchi Sand, vice president of the flight attendants' association, which has 447 members employed at Texas International.

She said TI flight attendants "with years of flying and seniority are being cast aside in favor of new hires employed under substantially inferior rates of pay and working conditions."

Spokesmen for the other unions delivered similar messages, saying that New York Air is a thinly veiled attack on unionism in the TI empire. "What we have here is a Macy's opening a candy shop in its store, and calling the candy shop "Woolworth's just so that new workers can be hired at lower pay," a Machinists spokesman said.

For example, John Bradley, contract manager for the pilots' association, said New York Air is paying its nonunion pilots about $25 to $30 an hour -- 50 percent less than that paid to TI's union pilots.

A spokesman for New York Air which held "inaugural ceremonies" in New York yesterday for its new crews, agreed that the new airline would pay lower salaries.

"This is in no way an anti-union company. We don't know what the future will bring in terms of unionization," the spokesman said.

He said the problem is that the TI unions assumed "they automatically would have contracts with us because they have contracts with Texas International." He said the new airline's officials "disagree with that contention."

New York Air's 10 roundtrips daily to La Guardia will start with fares 20 percent to 50 percent below the shuttles operated by unionized Eastern Airlines, which charges $60 each way. "In order to be low-fare, we have to be low-cost," said the New York Air spokesman, who requested anonymity.

The spokesman added that the 16 new pilots signed on yesterday "probably wouldn't have their jobs" if the TI contract with the pilot's association automatically applied to New York Air.

"They would not have been eligible for reasons of seniority. Under the terms of the contract, every pilot at TI would have been able to bid on the New York Air jobs before the guys we hired," the spokesman said.

However, the spokesman said the New York Air pilots, drawn from the military services and the private sector, are as qualified to fly as their counterparts at Texas International.