The Transportation Department ordered airlines yesterday to use more sensitive X-ray machines and to match all checked luggage to passengers on international flights.

In a partial response to a presidential commission that called for "major reforms" in government response to air terrorism, Transportation Secretary Samuel K. Skinner also announced creation of a new office of Intelligence and Security. A new assistant administrator's post also was added to the Federal Aviation Administration.

The orders addressed only a handful of the scores of recommendations issued by the seven-member commission in May after its examination of the Dec. 21, 1988, bombing of Pan Am Flight 103, in which 270 people were killed.

Panel chairwoman Ann Dore McLaughlin said she was "very encouraged" by the initial actions. "They're doing what they can to make the kinds of changes we all know are necessary," she said.

Sen. Frank R. Lautenberg (D-N.J.), a commission member, also praised the actions and said he was working on legislation that would meet some commission goals: Federal security managers at domestic airports, tighter controls on cargo, better training of airport personnel and compensation for terrorism victims. None of those items was addressed in Skinner's actions.

Another panel member, Sen. Alfonse M. D'Amato (R-N.Y.), said Skinner's response was a "good start," but he urged quick appointment of FAA security managers at key airports "because we cannot allow the present system to continue."

The commission called for preemptive and retaliatory military strikes against terrorists, a system to notify passengers of credible terrorist threats and several other steps to avert terrorist strikes both in the United States and abroad.

Skinner said the new office to oversee all transportation security would be headed by Coast Guard Vice Adm. Clyde E. Robbins, now commander of the Coast Guard's Pacific area and Maritime Defense Zone. No appointment was announced for the new FAA position.