Protectionist measures in the industrial countries have been mounting, the International Monetary Fund said yesterday in a report on currency exchange restrictions last year and in early 1981.

At the same time, the non-oil developing countries, facing higher prices for oil and greater debt burdens, also have been adopting more restrictive exchange and trade regulations. Altogether, in another of its series of relatively pessimistic economic appraisals, the IMF painted a picture of an inward-looking world in which higher energy costs and tougher competition from imports are eroding liberal trade commitments.

In volume terms, the growth of world trade was only 1.5 percent in 1980, the smallest increase in five years, and far below the average of the 1970s. In this environment, the report said, the effort of the developing countries to gain greater access to the markets of the industrial countries -- one of the goals of the Cancun North-South summit -- "has vitually stalled."

If there is a glimmer of hope, it has been the willingness of the richer nations "to resist the adoption of generalized restrictions on foreign trade." But specific protection has been won, the report said, in textiles, clothing, footwear, steel, shipping and certain consumer electronics industries.

Despite "the further intensification of payments difficulties," the developing countries did not increase their exchange restrictions significantly, the IMF said. It estimated that external payments arrears of 26 countries had declined slight to 5.3 billion special drawing rights (about $6.5 billion) at the end of 1980. This is equal to 42 percent total.

This compares with outstanding arrears of SDR 700 million (about $850 million) in 13 countries incurring arrears in 1975, equivalent to less than 10 percent of the value of exports that year.

"Without the refinancing or rescheduling of a substantial amount of debt service by official and commercial bank creditors tha took place in three countries, outstanding arrears would have continued their upward trend in 1980. . . ," the report said.

The report observed that the current account (trade and services together) of the seven major industrial countries had swung into heavy deficit in 1980, but is expected to shift into surplus this year. This analysis did not distinguish among the major industrial nations, but U.S. Treasury officials have said that the decline in U.S. price competitiveness following the steep climb of the dollar will push the U.S. current account into deficit next year.

Former Treasury Assistant Secretary C. Fred Bergsten is predicting a sharp swing from surplus to deficit. In a forthcoming monetary crisis.

But the view of the Reagan administration is that the dollar can remain stable, even in the face of a big current account deficit, if the U.S. domestic economy shows signs of responding to the Reagan economic measures.