Jonathan H. Newman in New York Times Real Estate Section, THE RULES ON EVICTING A REGULATED RENTER, October 7, 2007.

Q. I would like to know under what circumstances the tenant in a rent-regulated apartment can be evicted or forced to buy an apartment. For instance, if a rent-regulated tenant lives in a building that is sold to a new owner, can the new owner evict the tenant? If the apartment is in a co-op or condo, can the owner force the tenant to buy the unit?

A. “Tenants can never be forced to buy their apartments,” said Jonathan H. Newman, a Manhattan real estate lawyer. In addition, Mr. Newman said, rent-regulated tenants generally cannot be evicted from their apartments — provided they comply with the terms of their leases and pay their rents — regardless of who the owner is. So, if a new owner buys a building with rent-regulated tenants, the new owner cannot evict them unless they violate their leases or fail to pay rent.

When a building is converted to a co-op or condo, however, things can be a little different. Mr. Newman said that in New York, under the state’s Martin Act, a conversion takes place either under an eviction plan or a noneviction plan.

Under a noneviction conversion, the usual type, the sponsor must get at least 15 percent of the tenants to agree to buy their apartments before the plan can be declared effective. Once that number is reached, the conversion can go through, but tenants who have not agreed to buy must be allowed to remain in their apartments as rent-stabilized tenants.

If the conversion is made under an eviction plan, which is relatively uncommon in New York, more than 50 percent of the tenants must agree to buy their apartments for the conversion to be declared effective. Tenants who decline to buy can be evicted three years after the conversion’s effective date.