NEW YORK, N.Y., September 23, 2005 – The New York Mercantile Exchange, Inc., today announced margin increases for its nitrogen oxide emissions futures contract, effective at the close of business on Monday.

Margins on all months of the contract will increase to $2,000 from $1,000 for clearing members, to $2,200 from $1,100 for members, and to $2,700 from $1,350 for customers.