For most of his government career former Central Intelligence Director William E. Colby was in the business of gathering intelligence abroad and bringing it home to Washington.

Now, following a well-established Washington tradition, Colby is negotiating with a Tokyo-based public relations firm to monitor the Washinton political scene for a group of Japanese business interests.

Colby, who is now in private law practice here, was approached by the newly formed Center for Political Public Relations in Tokyo. The firm is headed by publisher Takayoshi Miyagawa, who last year published a critical book by a Japanese journalist on the exploits of the CIA. Colby was one of those interviewed for the book.

Colby said that when the current negotiations are concluded he will register with the Justice Department under the Foreign Agents Registration Act.

His predecessor as CIA director, Richard M. Helms, earlier set up a firm to work in behalf of Iranian companies after leaving his position as U.S. Ambassador to Iran last year. The rolls of the Foreign Registration Section at Justice are replete with former high-ranking government officials who expertise and contacts have been hired by foreign principals.

Miyagawa, who accompanied Japanese Prime Minister Takeo Fukuda on his current trip and is a close political associate of the prime minister, said he hoped that Colby would help him and his clients evaluate important political and economic issues in Washington, but no lobby for Japanese interests in the U.S. government.

A public controversy has arisen in the Japanese press over large fees paid both by the government and private business groups in Japan to Washington lawyers and public relations advisers.

Miyagawa suggested that one of Colby's mission may be to find out what the Japanese principals were getting for their dollars to satisfy their yen for influence in Washington.