Q. I will be moving out of my apartment before my lease expires. What is the legal procedure for breaking one's lease? . . . Khalika Eodumegwuhu-Sanchez, Brooklyn.

A. Lucas A. Ferrara, a Manhattan real estate lawyer, said that neither a landlord nor a tenant is permitted to break a lease unless the right to do so is in the lease agreement or given to the parties by a statute or regulation. For example, he said, a rent-regulated tenant who does not occupy an apartment as a primary residence could forfeit the right to the apartment.

Otherwise, Mr. Ferrara said, "a landlord must permit a tenant to remain in an apartment for the balance of the lease, while a tenant, in turn, is usually responsible for the payment of all rent."

Exceptions, however, could exist. For example, Mr. Ferrara said, when a tenant is forced to leave an apartment because all or part of the space is unusable, that could be a justification for breaking the lease. "If a tenant leaves because of issues relating to the apartment's livability, that could excuse a tenant from having to pay the rent for the time remaining on the lease," he said.

Otherwise, Mr. Ferrara said, market forces will play a critical role in a tenant's ability to break a lease without being held liable for damages.

"If the rent being paid is under market, and a landlord can increase income by leasing to a new tenant, a vacancy maybe welcome news," he said. He added, however, that problems may arise when the owner has a difficult time finding a new tenant at the existing rent or is forced to rent the apartment for less money.

In such situations, Mr. Ferrara said, a tenant about to break a lease would be better off informing the landlord immediately.

"In my experience, in the interest of avoiding litigation, many landlords will work with their tenants to find a mutually acceptable solution," he said, such as releasing the tenant from the remainder of the lease in exchange for a waiver of the return of the security deposit and/or pre-payment of several months' rent.

Mr. Ferrara said that in situations where an agreement cannot be reached, and the tenant breaks the lease, the legal question of whether the landlord is required to try to re rent the apartment - and minimize damages for which the tenant is responsible - depends in large part on where the building is situated.

As far as New York City is concerned, in Brooklyn, Queens and Staten Island, a landlord is usually required to mitigate damages by making reasonable efforts to find a new tenant. In Manhattan and the Bronx, however, an appeals court ruled in 1997 that the owner has no such obligation.