Turkish Prime Minister Bulent Ecevit, in an apparent softening of his earlier public stance against reopening U.S. bases in Turkey, said yesterday that it would be "no problem" to reactivate the intelligence-gathering installations once Congress lifts the U.S. arms embargo against Turkey.

"We have agreed with the United States that as soon as the embargo is lifted we shall promptly start working on a new arrangement for these installations, so it will be no problem," Ecevitt said in an interview.

Reopening the bases, closed by Turkey in 1975 in retaliation to the embargo, would "depend on some sort of legal agreement. But I don't think there would be difficulty in reaching such an agreement," Ecevit said.

In other conciliatory remarks, the Turkish prime minister said he would press ahead with efforts to solve the Cyprus dispute regardless of whether the embargo was lifted or not, and would not pull Turkey out of NATO "unless forced to."

Handing out cigarettes in a silver case given him recently by Greek Premier Constantine Karamanlis, Ecevit said he hoped the two leaders could meet again soon to "speed up soluations" to problems between their countries.

"The times element is important," Ecevit said. "With every day of continuing tension and arms race between Turkey and Greece, both countries are the losers."

He argued that the U.S. arms embargo, imposed on Turkey following its 1974 invasion of Cyprus, had not, as Congress had hoped, helped solve the Cyprus dispute and other differences between Greece and Turkey.

"I think it has become obvious to everyone that the American embargo has not eased the solution of these problems but has rendered them more difficult, Ecevit said.

"Not only because it is difficult for Turkey to act under pressure, but also because as long as such pressure continues the Greek Cypriots believe they can continue to adopt an intransigent attitude," Ecevit said.

Additionally, he argued, the embargo had weakened Turkey militarily and reduced its capability of defending NATO's southeast flank along its 379-mile Soviet border.

The lifting of the embargo, Ecevit insisted, was therefore "at least as important for our allies as it is for Turkey."

Asked whether Turkey would pull out of NATO if Congress did not approve President Carter's proposal to life the embargo and resume military aid, Ecevit replied:

"NATO has an important function in preserving peace and security - components on which detente is based. Turkey has a stake in detente being situated in such a critical part of the world and we wouldn't want to leave NATO unless we were forced too."

But if arms shipments were not resumed, Ecevit said, Turkey "would have to work out other alternatives to secure its national defense and independence."

Since defense and foreign policy are interrelated this would "naturally mean certain changes in Turkey's international relations," including, Ecevit said, a more neutral role in world politics.

Regardless of whether the embargo was lifted, Ecevit said, his government had decided to work out a "new national defense concept" making it less dependent on its allies, particularly the United States, for future arms supplies.

But he indicated that there would be no suddent shift in Turkey's present pro-Western alignment.