Exxon Corp. and Bankers Trust New York Co. yesterday said the Japanese Ministry of Finance has approved their joint application to set up a securities underwriting and trading firm in Japan.

The combination of the nation's largest oil company and one of the largest banks is the result of a quirk in Japanese law requiring that foreign banks seeking to go into the brokerage business in Japan join forces with a company or investor with no banking interest.

The Japanese have taken steps to open their securities industry to foreign firms in an effort to quell criticism in Congress and elsewhere that Japanese firms have increased their positions in the U.S. securities market while foreign firms have been all but blocked from entering the fast-growing Japanese market.

Earlier this year, Japan invited several foreign financial institutions, including four U.S. banks, to apply to open brokerage firms. A joint application from J.P. Morgan & Co. Inc. and construction giant Bechtel was approved last month. Still awaiting approval are applications from two other teams, one consisting of Manufacturers Hanover Corp. and Chrysler Corp., the other of Chemical New York Corp. and a private British investor.

Exxon will be a sort of silent partner in the combined Japanese operation, which will be based in Hong Kong to further comply with Japanese law on foreign ownership.

Each company will own 50 percent of the company, which will be called BT Asia Securities Ltd., but Bankers Trust will operate the brokerage office, which is expected to open in Tokyo later this year. Bankers Trust already has a branch in Tokyo and has owned a trust bank there for two years.

The company will be able to both underwrite stock offerings and trade stock, although some experts have questioned whether Japanese securities firms will readily do business with the new foreign firms or include them in major underwriting syndicates.

William Smith, a spokesman for New York-based Exxon, said the partnership with Bankers Trust in Japan represented a unique opportunity, and Exxon has no plans to move into the securities business in any other part of the world. "We went in it because we believe it will allow us to take advantage of the many opportunities in {Japan}, in conjunction with a partner that has a proven track record in Japan," Smith said