City janitors threatened yesterday to sweep in the new year with a strike that would leave cubicle denizens in more than 1,000 office buildings stuck holding the mop.

At a massive Midtown rally, hundreds of members of Local 32BJ of the Service Employees International Union said they'll walk off the job when their contract expires Dec. 31 unless they receive what they called a "fair share" of the recent real-estate boom. "If we don't get it, we are more than ready to strike," shouted Hector Figueroa, secretary-treasurer of the union. "The industry can afford it!"

Office space rents increased 47 percent over the past three years, according to the union.
More than 26,000 janitors, lobby attendants, maintenance workers and other support staffers are represented by the union. Talks ended yesterday, but should resume today.
"We have made what we believe to be a substantive offer, and we will work through the weekend and longer, if necessary, to reach an agreement," said James Berg, president of the Realty Advisory Board, an owner association.

The workers make about $40,500 a year, have a pension and do not pay premiums for health insurance. In the last contract , workers received 1.7 percent raises. Owners injected $175 million into the health plan. The association has called the union demands unrealistic.