The New York Mercantile Exchange Building at One North End Ave. on the Hudson River in the World Financial Center is being officially gobbled up by its neighboring owner, Brookfield Office Properties.

Downtown snoops tell us Brookfield signed a contract earlier this week to pay $200 million for the 16-story office building, which like all the Battery Park City buildings is on a long-term lease from the Battery Park City Authority until June 2069.

The deal works out to roughly $385 a square foot, and seller — Chicago-based CME — is expected to lease it for two years and then restack its energy market trading operation into the lower 220,000 square feet for 13 years at a rent expected to be in the $50s per square foot.

This would give Brookfield about 300,000 square feet on the upper floors to lease to other companies, and perhaps fill in a double height trading floor to add an additional 30,000 feet.

By locking in the deal, Brookfield keeps other possible building owners from undercutting it or competing with its own Brookfield Place leasing campaigns.

Holly Duran Real Estate Partners of Chicago, along with locals such as Newmark Grubb Knight Frank’s CEO Jimmy Kuhn and Jennifer Schwartzman were marketing the building on behalf of CME. Both Brookfield’s spokeswoman, Melissa Coley, and Newmark’s spokeswoman, Mira Matic, declined comment.

The building was the headquarters of the Mercantile Exchange until CME bought the parent company for $9.8 billion in 2008.