The Turkish government today imposed stringent economic austerity measures after devaluing its lira 44 percent against the U.S. dollar.

The belt-tightening measure included price increases of between 25 to 65 percent on wine, beer and other spirits while prices on gasoline and petroleum products were raised by up to 25 percent. Sales of iron and steel products were banned until Wednesday in anticipation of price increases on such items.

The austerity measures announced by Prime Minister Bulent Ecevit's government had been demanded by the International Monetary Fun before more than $1.5 billion in new credits could be released.

The credits to be extended by the United States and other members of the Organization for Economic Cooperation and Development were made conditional on Turkey's meeting IMF conditions.

The measures were greeted with an almost audible groan from the already hard-pressed nation, which is undergoing the worst economic crisis in its modern history. It includes 70 percent inflation and 25 percent unemployment. An estimated 90 percent of Turkey's export earnings in 1979 will have to be used to pay for oil imports.

Increased expenditures for oil imports, causing successive balance of payments deficits, have raised Turkey's foreign debt to about $12 billion. Contributing to the deficits were Turkey's arms purchases after a U.S. arms embargo that followed the 1974 Turkish invasion of Cyprus was lifted.

Ecevit had resisted pressures to comply with IMF demands, hoping that he could obtain economic assistance from the United States because the value of U.S. intelligence-gathering bases in Turkey has increased following the closings of similar U.S. bases in Iran.

Apart fom bases that are used to monitor Soviet compliance with the terms of U.S.-Soviet strategic arms limitation accords, Washington is hoping to use Turkish air space for high-altitude U2 flight to verify Russian compliance with the terms of the newly concluded SALT II pact.

But Ecevit and his aides have come to the conclusion that unless a compromise about economic belt-tightening was reached, Turkey's NATO allies would not be able to assist Turkey regardless of the country's strategic importance.

As a result, Ecevit introduced a mulitple exchange rate system as a face-saving device for effective devaluation. The value of the lira was decreased from 26.50 to 47.10 to the dollar.

But the system provides for exceptions that include the country's oil and fertilizer imports and agricultural exports. For these items the rate would be 35 lira to the dollar, or a 24 percent devaluation.

Lira values to other Western currencies will be set with reference to their value against the dollar.

Turkish Finance Minister Zieya Muezzinoglu was scheduled to fly to Paris Wednesday to complete the credit agreements with the Western countries.

Ecevit, who rules with a slim majority in the parliament, has been losing popularity as a result of the country's economic difficulties and social turmoil they have helped create. The most populous of Turkey's 67 provinces are under martial law.

Observers here believe that Ecevit is unlikely to remain in power if the new economic measures and Western credits do not at least contain the current crisis.