Yamashita-Shinnihon Steamship Co., known as Y.S. Line, is developing new ways to cut costs as it struggles to cope with continued financial losses.

Among other steps, it is transferring some expenses from yen into dollars and placing some of its vessels under Panamanian flag. The company also is improving its computer links both internally and with customers, says Yoshio Kojima, general manager of the company's North American headquarters.The Japanese carrier will still record a substantial loss in the fiscal year about to end, but it will be less than in the previous year.

Mr. Kojima said in an interview that the loss from its North American service will be $30 million to $40 million in the fiscal year ending March 31, using a recent exchange rate. This is down from a loss of about $50 million in the previous fiscal year, based on an earlier exchange rate.

A major problem for Y.S. Line and other Japanese shipping lines has been the sharp appreciation of the yen against the dollar over the last two-and-a- half years. Most revenues are collected in dollars, and when these are converted to yen, the value of the companies' earnings is reduced.

Freight rates on the trans-Pacific trade, the largest route in the world, are under pressure from overcapacity and fierce competition.

Both Sea-Land Service Inc. and American President Lines Ltd., the two U.S.-flag carriers in the trade, have been particularly competitive in establishing strong intermodal railconnections for cargo from Asia that moves

from West Coast ports. The basic area of new competition is in inland transportation, said Edward Kelly, executive vice president of Y.S. Line.

A government-sponsored committee in Japan, the Council for Rationalization of Shipping and Shipbuilding Industries, is expected to make its recommendations to the Ministry of Transportation by June. Some possible regrouping among the lines is expected, industry executives say.

The report will depend on the status of each carrier, said Mr. Kojima. There are many factors to consider.

Showa Line Ltd. recently announced its decision to pull out of the liner business. Japan Line will end its all-water service to the U.S. East Coast, concentrating on its intermodal service through the West Coast. (See related story.)

From the standpoint of Y.S. Line, we have no reason to change or withdraw services in the Atlantic or the Pacific, said Mr. Kojima. The other Japanese lines are Nippon Yusen Kaisha (NYK Line), considered the biggest worldwide, Mitsui O.S.K. Lines and Kawasaki Kisen Kaisha Ltd. (K Line).

Mr. Kojima and Mr. Kelly said the line's service on four routes is competitive with other carriers'. Its relatively small size allows it to respond quickly to customers' special requests, they said. We can hand-tailor our services, said Mr. Kelly.

As Y.S. Line aims to cut its losses, it is transferring some of its yen- denominated expenses into dollar-denominated ones, Mr. Kojima said.

By selling some of its vessels to an outside company, often a subsidiary or affiliate of Y.S. Line, the line can then charter the vessel on a dollar basis, he said. By operating under a foreign flag, companies can reduce expenses by using lower-wage crews.

Y.S. Line also is considering shifting some of its office operations to the United States and Hong Kong from Tokyo, he said. That would help to reduce its yen-denominated expenses, he said.

The company has cut its work force as part of a restructuring plan that began two years ago. While Mr. Kojima declined to provide details, he said the company plans further reductions in its labor force. The company now employs about 400 office workers and 800 seamen, he said. In 1986, it employed about 1,900 people.

Since the restructuring effort began, the yen has continued to rise sharply against the U.S. dollar. We must offset the impact by further rationalization, Mr. Kojima said.

Y.S. Line plans to put a new vessel that comes into service this June on the trans-Pacific route under the Panamanian flag. The ship will hold 2,800 20-foot containers and replace a vessel with a capacity of 1,400 TEUs.

One of the five vessels that Y.S. Line employs in a space-chartering agreement on the trans-Pacific sails under the Panamanian flag. The chartered vessel has a non-Japanese Asian crew.

The company operates a weekly service on the trans-Pacific in a space- chartering arrangement with Singapore-based Neptune Orient Lines Ltd. and Hong Kong-based Orient Overseas Container Lines. The three companies, each operating five vessels, offer three shared routes: Hong Kong and Taiwan to California; Japan and South Korea to California; and Hong Kong, Taiwan and Japan to the Pacific Northwest.

In an all-water service to the U.S. East Coast, Y.S. Line operates one vessel in a space-chartering agreement with two of Japan's biggest carriers, NYK Line and Mitsui O.S.K.

Overall, Y.S. Line reported a $71.8 million loss for the last fiscal year, using the exchange rate applicable when the report was made. The company's liner services account for about 45 percent of total revenue. Some 80 percent of liner service revenue derives from its North American operations.

Dry bulk operations account for some 50 percent of total revenue for the company, with the oil tanker division accounting for the remaining 5 percent.

The Japanese Ministry of Transportation in Tokyo told The Journal of Commerce that five Japanese lines lost $478.9 million in the fiscal year ending in March last year 1986 at present exchange rates. The only one to report a profit was NYK Line, which had net income of $1.8 million for the period, mostly from its real estate and financial operations.