An international liaison program instituted by the police department is gaining traction after Commissioner Raymond Kelly signed an agreement that will allow the Madrid police department to station an officer in New York City.

Law enforcement officials from the city and from Madrid gathered at One Police Plaza yesterday to sign the formal agreement.

“Today’s signing formalizes an outstanding relationship between the NYPD and our counterparts in Madrid to thwart threats of terrorism against both municipalities,” Mr. Kelly said in a statement.

In 2002, the police department’s intelligence division began assigning detectives to become liaisons in foreign countries. The program, designed to collect intelligence for the city’s police department, has grown to 10 cities around the world, including Madrid.

With yesterday’s agreement, Madrid’s police department becomes one of a growing number of international law enforcement agencies stationing officers in New York. Currently, officers from the national police departments of Jordan, Jamaica, and South Korea, as well as the city of Toronto, are working at police headquarters.

As police departments around the world seek to imitate New York City’s counterterrorism programs, sending officers to the city to learn from its experts is seen as beneficial, a senior fellow for counterterrorism at the Manhattan Institute, R.P. Eddy, said.

The police department’s head spokesman, Deputy Commissioner Paul Browne, said the NYPD does not lobby other police departments to station officers in the city and that it is selective about who is invited.

Most police departments around the world receive less funding than the city’s police department, making it more difficult to sponsor initiatives such as the liaison program, Mr. Eddy said.