The Sony Corp. of America, one of the country's largest sellers of electronics equipment, yesterday announced increases for many of its consumer and professional product lines, saying they did so because of the continuing fall of the dollar.

Sony said the suggested retail prices on a range of its popular products will be raised between 5 percent and 7 percent, following increases of 5 percent to 20 percent in selected items last fall.

Similar action by Sony's competitors and other major foreign suppliers could signal a new jolt of higher prices and inflation for the U.S. economy, triggered by the fall of the dollar.

It is unclear, however, how Sony's announcement would affect consumer prices in the intensely competitive consumer electronics market.

Suggested retail prices normally function as a benchmark against which dealers offer discounts. How much of the higher wholesale prices that they will pass on to their customers will be up to individual retailers.

Sony said suggested retail prices of certain sets with screens of 20 inches and over would rise an average 5 percent. Audio products' suggested prices would rise 6 percent, with Betamax videocassette decks going up at a somewhat lower rate, and most professional products' suggested prices rising 7 percent. Further rises, for audio tape, will be implemented in the spring, Sony said.

The company declined to give figures for changes in what it will charge dealers and wholesalers under the new pricing structure. But it said they were in the range of the rises in the suggested retail prices.

"Economic events in recent months have created an absolute necessity for price rises to supplement those normally built into model change-overs," said Neil Vander Dussen, president of Sony Corp. of America, which is the U.S. arm of the giant Sony Corp. of Japan. This was needed, he said, to maintain "an acceptable and realistic level of profitability."

Since February 1985, the dollar's value has fallen more than 50 percent against the Japanese yen and the West German mark, coaxed along at various points by the Reagan administration, which has hoped that a cheaper dollar would make American-made goods more competitive on world markets and slow the flow of imports into the U.S. economy.

Despite the dollar's dramatic decline and the rise of the yen, however, increases in retail prices of many Japanese products in the United States have not kept pace, particularly electronics prices.

"They've been trying to hold down prices, but in the process taking a big hit on profits," said David Wyss, chief financial economist for Data Resources Inc. of Lexington, Mass. This is standard operating procedure in Japan's corporate culture, which tends to stress market share rather than profits.

The companies have also held the line by aggressively trimming costs and increasing productivity in their home plants and shifting manufacturing to lower-cost environments such as Taiwan, South Korea and the United States.

But every time the dollar falls against the yen, now edging toward another historic low of 120 yen, the pressure mounts for Japanese exporters to raise prices in the United States or sell at a loss.

According to Data Resources, Japanese car makers have raised their prices about 8 percent for the new 1988 model year. German auto makers have upped their prices 10 percent to 12 percent. Data Resources estimates that in 1987, prices of imported consumer goods of all types rose 9 percent, imported cars 7 percent, industrial supplies 11 percent and capital goods 1 percent.

The Matsushita group, the largest Japanese electronic goods producer, raised U.S. prices on selected goods last summer and again in November. Spokesman Ken Shimba yesterday said the company has no plans for further increases, but will "watch the situation carefully."