Merger of subway police officers with the city's regular police force was formally approved Friday and will take effect a minute after midnight Sunday.
In an 8-0 vote, the Metropolitan Transportation Authority Board approved a memorandum of understanding that joins 4,300 transit officers with the 30,000-member NYPD.
"New York City will have not just the 'the finest,' but 'the largest' police department in the United States," Mayor Rudolph W. Giuliani said.
The mayor also is seeking to merge 2,500 Housing Authority police with the city police officers, an effort now tied up in court by the officers' union.
Union officials in both the Transit and Housing Patrolmen's Benevolent Associations had balked at merger in years past because they wanted assurances that pensions, promotions and seniority would be protected.
Giuliani, speaking on his regular Friday morning call-in radio show, credited former Mayor Edward I. Koch and "other mayors" as laying the groundwork for the merger. Giuliani's predecessor, David N. Dinkins, was among them.