In an attempt to meet U.S. commitments to Taiwan without angering China, the Carter administration offered yesterday to sell Taiwan 48 missile-equipped F5E jet fighters, while rejecting a Taiwanese bid for more advanced planes capable of attacking mainland China.

In announcing the offer to augment Taiwan's existing fleet of F5Es, the State Department noted that it has turned down Taiwan's request for more powerful planes with longer ranges, such as the F4, F16 or F18.

Administration sources said privately the decision was a big disappointment to Taiwan, which had wanted the F4, a long-range plane capable of carrying a wide array of armament.

To ease the disappointment, the sources added, the administration is offering to equip the new F5Es with Maverick air-to-ground missiles that could be used against attacking ships in the straits between Taiwan and China.

"The F5E, which will be offered to Taiwan with its improved armament, will provide an additional capability to help meet Taiwan's defense requirements," said Jill Schuker, a State Department spokeswoman. "The United States will continue to be responsive to Taiwan's legitimate defense needs."

Implicit in her statement was a strong hint of the delicate balancing act involved in dealing with Taiwan's request for planes.

Under commitments in effect since the 1949 Communist takeover of China, the United States has pledged to help Taiwan defend itself against attack from the mainland. But, wanting now to move toward normal relations with China, Washington is also anxious to avoid steps in its assistance to Taiwan that might unduly alarm or anger the Peking government.

The result has been months of indecisive backing and filling by the administration, while it tried to figure a way of dealing with this dilemma.

Taiwan is in the midst of a program to buy and assemble 200 F5Es, using parts provided by the plane's American manufacturer, Northrop Corp. The F5E, widely used by Third World countries and small West European air forces, is essentially a defensive aircraft with a combat range of roughly 150 miles.

The Taiwanese wanted to augment their F5E fleet with approximately 60 F4 Phantoms, the longer-range U.S. workhorse of the Vietnam war. But the administration, concerned about the reaction in Peking, ruled out the sale of F4s and other long-range jets.

Last summer, Washington tried to finesse the situation by announcing it would agree to Taiwan's purchase of the Kfir, and Israeli-made fighter with an American engine that is considered slightly more sophisticated than the F5E. However, the Taiwanese didn't show any enthusiasm for that idea.

Then the administration considered offering Taiwan the projected successor to the F5E, which is known as the F5G. Still on the drawing boards, it is intended to have one big engine rather than the two smaller ones used by the F5E, and could carry a larger armament load.

Schuker said yesterday, though, that the administration "has not addressed" the question of providing the F5G because a decision has not yet been made about whether to actually put it in production.

Administration sources said sales of more than 300 F5Gs would be required to recover its development costs. Since Taiwan only wants 60 and since it is unclear whether other countries would be willing to purchase this newer model, there are big questions about whether the plane will ever be produced, the sources said.

In addition, they added, producing F5G solely for Taiwan's use apparently would run counter to President Carter's 1977 guidelines said, "Development or significant modification of advanced weapons systems solely for export will not be permitted."

The result, the sources said, was a decision to offer Taiwan additional F5Es an dto sweeten the deal by equipping them with the Maverick missiles as well as the air-to-air Side-winder missiles that Taiwan's current F5Es carry as weapon against other planes.

The announcement made by Schuker said repeatedly that the F5Es are a defensive weapon that will not violate the administration's policy goal of not disturbing the arms balance in senitive areas of the world through the introduction of sophisticated new weaponry.

She said the Taiwan government had not yet responded to the offer. However, the sources noting that otehr countries manufacturing advanced jet fighters such as France and Britain will not sell plances to Taiwan because they fear damage to their relations with China, said they were confident Taiwan would have no choice other than to accept the U.S. proposal.

Administration officials were unable to say how much the planes will cost. The basic, stripped-down version of the F5E, when sold abroad, costs about $3.5 million per plane; but the cost can go as high as $5 million if the purchase includes expensive additional armaments and auxiliary equipment.

On the other hand, the sources pointed out, the fact that the planes would be assembled in Taiwan rather than in the United States would reduce some of the basic cost.