Secretary of State Edmund S. Muskie, on the eve of a meeting with NATO allies, reported encouraging signs today for a new U.S. bases agrement with Greece but indicated that a proposed U.S. arrangement to use military facilities in Somalia has run into trouble.

Muskie's report on the military arrangements followed separate meetings here with the foreign ministers and other high officials of Greece and Turkey in preparation for a semiannual meeting of the North Atlantic Treaty Organization Wednesday and Thursday.

Greece, which pulled out of military participation in the Atlantic alliance in 1974, is "agreeable to moving forward" on reintegration into NATO and on a new U.S. bases agreement, said Muskie.

Other State Department officials who visited Athens recently reported that a basic decision seems to have been taken to settle outstanding issues both with the Western alliances as a whole and the United States within the next year.

The United States has continued using military facilities in Greece on a restricted basis even though negotiations have long been stalled on a new bases agreement between the two nations to replace a pact that lapsed. Completion of the new arrangement would probably lead to expanded use of greek facilities by the United States.

Muskie noted following his conference here with Greek Foreign Minister Constantine Mitsotakis that the details of "sticky issues" remain to be settled. This appeared to be a reference to Greece's claim to control of nearly all the air space over the Aegean Sea, a claim that is unacceptable to Turkey.

NATO Seccretary General Joseph Luns, speaking at a press conference welcomed a Turkish declaration that it will not seek to block Greek reintegration into NATO. But Luns added that we are not out of woods yet" on the Greek issue, which is of fundamental importance to the southern flank of the alliance.

A new U.S. bases accord with Turkey has been completed but not ratified.

Muskie said Turkish Prime Minister Suleyman Demirel told him today that the Turkish parliament is prepared to ratify the agreement. Demirel's hold on political power is shaky, however, and the fate of his government hangs in the balance in daily conference with key members of the ruling coalition.

As for Somalia, one of three Indian Ocean sites being sought by the United States for supporting of expanded military activities near the Persian Gulf, Muskie was unusually negative in remarks to reporters.

Muskie denied that "a strategic decision" ever had been made that Somali facilities are needed, and said questions must be answered before agreement with Somalia is possible.

A U.S. facilities pact has ben signed with Oman, another of the Indian Ocean sites, and negotiations are nearing completion of a similar agreement with Kenya.

Washington is reported to have offered Somalia about $400 million in aid, but Somalia is said to be asking several times that sum. The U.S. is also insisting on assurances, which somalia has been reluctant to give in the past, that American military equipment and supplies will not be used by the Somalis in their war to capture the disputed area of the Ogaden in neighboring Ethiopia.

As he has repeatedly said in recent days, Muskie expressed skepticism about the Soviet announcement of troop withdrawals from Afghanistan. Muskie said today that he has "no evidence to suggest that there is a net reduction" of Soviet forces in the Afghan area. He indicated that so far what is involved is only a redeployment of troops from Aghanistan to Soviet areas on the Afghan frontier.

Muskie said the Soviet announcement may have been intended to "throw a curve ball" at the Venice summit meeting or to improve the attendance at the Olympics in Moscow next month.

The Soviet announcement did not create disvisiveness among the leaders at Venice "even for a moment," Muskie said.