In an unprecedented action, Texas International Airlines has asked the Civil Aeronautics Board for permission to put itself in the hands of independent trustees and allow its parent company, Texas Air Corp., to assume immediate control of Continental Airlines.

The dramatic move intensifies an escalating takeover battle between officials of Texas International and the Los Angeles-based Continental, whose plans to merge with Western Airlines were spoiled when Texas International's tender offer for nearly half of Continental's stock was successful.

In a petition filed with the CAB at the close of business Friday, Texas International (TI) argued that the request for the unusual "reverse trust" was necessary to protect its $93 million investment in Continental.

That investment, in the form of 7.45 million shares of Continental, currently is being held in a trust to insulate TI from exercising any control over Continental while its application to acquire control is pending at the CAB. Approval is expected this summer. Under the trust agreements approved by the board last month, TI has authority to vote its shares only against the proposed Continental-Western merger.

Since that time Continental, in its efforts to block a merger with TI, has put forward a plan to issue 15.4 million shares of its stock to its employes -- more than doubling its current shares outstanding. The employes thus would acquire a controlling interest in the airline. They also would retain Continental's current management.

The plan, to be executed without a vote by shareholders, would result in the removal of Continental stock from the New York Stock Exchange list and have other detrimental effects on the value of Continental shares, Texas International has charged.

To block Continental's plans, TI proposed that the board move quickly to:

Permit TI to dissolve its Continental trust and transfer its Continental shares to Texas Air Corp. (TAC), its parent company. That would allow the parent company to exercise immediate control over Continental. This would include such corporate actions as electing directors at Continental's annual shareholder meeting, scheduled for May 6.

Allow Texas Air Corp. to create a new voting trust that would hold all of its Texas International stock. TI is now a wholly owned subsidiary of TAC. TI's board of directors would be replaced by a group of independent trustee-directors, approved by the CAB.

"This 'reverse trust' relief will permit TAC to take the step that any owner of 48 1/2 percent of the stock of an unregulated company could take in the face of the extraordinary plans that Continental management has proposed to protect their own positions to the detriment of all the Continental shareholders," TI's petition to CAB said.

Putting Texas International in trust effectively would insulate TAC from common control of Texas International and Continental until it has been approved by the board, the petition said. If the application for common control is not approved by the CAB, the petition said that TAC would submit for the board's approval a plan for the divestiture of either the entrusted Texas International stock or the Continental stock that TAC then would own directly.

The unusual petition to the board comes from a company and officials who have stunned the airline industry and Wall Street community with unusual moves in the past. Frank Lorenzo, chairman of TI's executive committee and president of TAC, was responsible for instituting TI's low "peanuts" fares, has made in excess of $40 million for the company in his unsuccessful bid for National Airlines, and created the low-fare New York Airlines, also a TAC subsidiary.