If Italy's massive balance of payments deficit is to be kept under control, middle-class and wealthy Italians are going to have to cut down on imported luxury goods, according to Italy's minister of foreign trade, Rinaldo Ossola.

In a controversial speech here recently, the former director general of the Bank of Italy surprised and irritated many of his fellow citizens by urging them to "Buy Italian." If Italians were to reduce their imports of foreign cars by only one-fourth, the country could save the equivalant of its recently negotiated $530 million International Monetary Fund loan, he said.

Instead, he pointed out, the value of imported luxury goods here has soared since 1975. Despite an ongoing, economic crisis, Italians currently import more whiskey than any other European country. They are also the major importers of orchids, and the world's second-place importers of Rolls Royces.

The "Buy Italian" proposal enraged importers and confused many Italians who have bitter memories of the disastrous policy of economic autarchy or self-reliance engineered in the 1930s by Fascist dictator Benito Mussolini.

But the foreign trade minister's main point was clearly to call attention to Italy's "fragile foreign reserves situation" - the result of a $6.6 billion trade deficit and medium- and short-term foreign debts amounting to close to $30 billion.

Ossola stressed, in fact, that he was not suggesting import restrictions of any kind, but merely that Italians think twice before choosing foreign goods over those locally made. Not only would this help Italy's employment levels, but limiting the outlay of foreign currency could facilitate a more expansionist economic policy at home, he said.

He pointed out that one-seventh of the trade deficit was money spent on luxury consumer goods like foreign-made liquours, cars, French flowers, motorcycles, yachts, television sets, fur coats, perfumes, cosmetics, musical instruments, crystal, watches and sound equipment.

In 1975 and 1976, imports here exceded exports by 44 per cent. Expansion of the export sector in the near future therefore cannot be counted on to bring the trade balance back into surplus, Ossola said.

Data compiled by the National Statistics Institute show that citizens of this economically troubled country nevertheless spent $26 million on imported whisky, $2 billion on imported cars, $54 million on fresh flowers and plants, $120 million on imported perfumes and cosmetics and about the same amount on foreign tobacco and cigarettes, $26 million on imported motorcycles, $25 million on fur coats, $48 million on imported fabrics, and $15.5 million on champagne.

In 1976, Italians bought 70 Rolls Royces at an average price of $72,000. Eighty-three more are on order. Another $6 million was spent on fashionable luxury items such as Ray-Ban sunglasses and Rolex watches.And despite the soaring international price of coffee, expenditures for that product are expected to reach $720 million this year.

Reactions to the Ossola proposal were mixed. The Communists pointed out that replacing foreign luxury goods with local luxury goods was not the best way to combat waste. Individual Italian complained that there were some solid reasons for not always buying Italian.

"Some of our foreign purchases are clearly due to snobbism and are therefore unnecessary," said Enzo, a Roman who runs a local delivery service. "But I bought a Ford instead of a Fiat simply because the model I wanted cost less and also because I would have had to wait several months for Fiat delivery. My brother bought a Merceders because there is no comparable Italian car currently on the market."