The Reagan administration, battling to save Philippines President Ferdinand Marcos from a fast-spreading communist insurgency, remains at loggerheads with a key House subcommittee that voted for a second straight year to drastically cut its military aid request.

The administration has asked for $100 million in military aid for the next fiscal year, a 150 percent increase over last year's $40 million authorization. But the House Foreign Affairs subcommittee on Asian and Pacific affairs, led by Rep. Stephen J. Solarz (D-N.Y.), has approved $25 million, arguing that the steep jump would be "a serious mistake" and would send "the wrong signal" to Marcos.

While cutting military aid, the subcommittee voted to boost the administration's economic aid request, from $95 million to $155 million, signaling its conviction that U.S. priorities should lie in promoting reform.

The Senate Foreign Relations Committee Wednesday narrowly defeated a Democrat-supported amendment by Sen. John F. Kerry (D-Mass.) that would have made more than $25 million in Philippines military aid contingent on President Reagan's certification that Marcos had made "significant progress" in human rights and that the Philippines Army had made "substantial reform" in eliminating corruption and mistreatment of civilians as well as a "substantial effort" to stop its "extra-judicial killings."

It approved the administration's original $100 million request, setting the stage for a battle between the House and Senate, and probably a final appropriation of slightly more than this year's $40 million in military aid.

Underlying the struggle over the military aid level is a far more fundamental disagreement between the administration and congressional opponents over their assessments of Marcos' intentions and how the United States should proceed in seeking to "reform" an ally who is in deep economic trouble, facing a spreading communist insurgency but clearly reluctant to make substantive concessions, even under mounting internal pressures.

"There are differing perceptions how best to go about getting the necessary [reforms] -- holding back aid or giving it and asking for them reforms ," Solarz said in an interview. "Our approach has a better chance of succeeding."

Solarz says the Philippines basically is in "a transition period" with Marcos on the way out, when it is far more important for the United States to forcefully place itself on the side of reform and change, rather than to worry about saving Marcos. This would preserve the U.S. position with his successors, if that is possible, Solarz says.

Both sides say the stakes are the future of the U.S. presence in the Philippines, including two long-established U.S. facilities there, Clark Air Force Base and Subic Bay Naval Base.

Richard L. Armitage, assistant secretary of defense for international security affairs, has told Congress that these bases are "essential" to the U.S. strategy of deploying forces in the Pacific and Indian Oceans and to countering the Soviet military buildup in Danang and Cam Ranh Bay in Vietnam.

Replacing them with facilities at other Pacific locations, he said in testimony March 21 before the House Appropriations subcommittee on military construction, would take several years and cost the United States "several billion dollars."

Administration spokesmen are warning that the rebel New People's Army, estimated to number between 10,000 and 12,000, could in three or four years reach a "strategic stalemate," in which the Philippines Army could no longer defeat it, if the trend continues and U.S. military aid is not stepped up.

Arguing in defense of the administration's request for $100 million in military aid, Armitage said in an interview that the Philippines Army has been deteriorating for 10 years, and "we don't have 10 years to get them back where they are a capable fighting force."

He said the bulk of the $100 million request for the Philippines Army is not for "big ticket items" such as helicopters, planes or ships, but for essentials such as spare parts, repair and maintenance of existing equipment and even trucks. "They have no trucks," he said, citing instances in which an entire battalion was sharing one truck.

"If we don't help the military, we will find ourselves with a much more narrow range of options. They need a great deal of money quickly, before we find the NPA [New People's Army] is at a position of strategic stalemate."

The Pentagon's top Philippines expert also argued that the Marcos government had sufficiently shown that it intends to make political, economic and military reforms to warrant giving it the full $100 million.

"The signals from the top have been right, correct, good, but it takes time to implement reforms," he said, adding that Congress should remember that the United States is not the "father" or "big brother" in the Philippines, capable of dictating reforms to Marcos.

Armitage clearly was concerned about the implications of a Marcos declaration that he intends to reinstate the former army forces chief of staff, Gen. Fabian Ver, if Ver is acquitted of charges of attempting to cover up military involvement in the assassination of opposition leader Benigno Aquino Jr.

"We'll have to see what authority he is given and be guided by the perception of the [Filipino] people about him," Armitage said. "We'd want to look at all conditiond. Does he have authority? Are reforms being instituted? There are many ifs and question marks . . . . We'd be up on the Hill consulting."

The view from the House, and from Solarz in particular, is one of deep skepticism about whether Marcos intends to carry out the necessary political or military changes or is capable of changing his outlook.

Marcos' statement about reinstating Ver if he is acquitted, Solarz said, is "an indication he is not serious about serious military reforms."

Solarz is demanding that "corrupt and inefficient officers" be replaced with "professional soldiers" and that a series of economic and political changes, such as an end to "crony capitalism" and rule by presidential decree, begin before military aid is increased.

Solarz said he is "not overly optimistic" that Marcos will ever take these steps, because "they would result in his political and economic emasculation."

Thus, granting Marcos a 150 percent increase in military aid, Solarz says, would simply "alienate the [Filipino] people without enhancing the effectiveness of the Philippines Armed Forces." It would even undermine the administration's effort to persuade Marcos to make real reforms, he says.

"Our position is a better hedge against the future in a transition period," he added. "We don't enhance our interests by dramatically increasing military aid."