The Environmental Protection Agency's chief international official has offered to resign in the wake of reports that he encouraged U.S. negotiators to accept the Dow Chemical Co.'s position on an international chemical testing agreement, according to agency officials.

Richard Funkhouser, director of the EPA's international affairs office, would be the 14th high-ranking official to step down amid congressional inquiries into allegations of improprieties at the agency.

A House Science and Technology subcommittee chaired by Rep. James H. Scheuer (D-N.Y.) has been investigating the roles of Funkhouser and a Dow executive, Donald D. McCollister, in a meeting in Paris last June of the Organization of Economic Cooperation and Development.

According to memos from Funkhouser to other EPA officials, which were obtained by the House subcommittee, McCollister briefed Ambassador Abraham Katz, the chief U.S. negotiator to the OECD, in a session that excluded both the EPA's official delegate to the meeting and a public-interest adviser.

Several months after that meeting, the OECD adopted, at U.S. insistence, a voluntary and diluted version of the testing system.

Funkhouser could not be reached for comment.

His resignation offer was confirmed by other EPA officials, who said William D. Ruckelshaus, President Reagan's nominee for EPA administrator, had indicated his desire to fill the international affairs job with Fitzhugh Green, a former Foreign Service officer who held a similar post in the agency under the last Republican administration.