As New York City residential renters reach the end of their leases, many are are getting their rents slashed. Rents dropped in the fourth quarter of 2009 over the same quarter in 2008. “A lot of tenants have been successfully renegotiating rents,” said Daniel Baum, CEO of TDG/TREGNY. Prudential Douglas Elliman’s rental market report, released today, says the average monthly rent of a Manhattan apartment in fourth-quarter 2009 was $3,789, 4.3 percent less than $3,958 in the same quarter of 2008. The best way to get the landlord to drop the rent is to hit him up at the end of the lease, Baum said. “Traditionally, an owner is not going to renegotiate a lease mid-term,” he noted. Another strategy to receive lower rents is to check out comparable prices in the building. Jordanna Dworkin, who rents a studio on the Upper East Side, found that an identical unit in her building was being rented for $400 less than she was paying. She immediately called her landlord and he agreed to lower her rent — saving her $4,800 a year.