July 18 (Bloomberg) -- The New York Mercantile Exchange, the world's largest energy market, is trying to break up Intercontinental Exchange Inc.'s planned purchase of the Winnipeg Commodity Exchange.

WCE Holdings Inc., parent company of the Winnipeg exchange, said yesterday that it had received an unsolicited C$50 million ($48 million) bid, topping Intercontinental's C$40 million offer. The bidder is Nymex Holdings Inc., according to a person familiar with the matter who asked not to be named because the information has not been made public.

Exchanges are buying regional operations such as Winnipeg or large companies such as the Chicago Board of Trade to grow and to become more competitive, said Mark Williams, a Boston University finance professor. Intercontinental on July 9 lost out to the Chicago Mercantile Exchange in a three-month bidding war for the Board of Trade.

``Time is what they're racing against,'' Williams said in an interview. ``The end game is to get critical mass quickly'' to fend off being acquired, he said.

Both Intercontinental and Nymex are possible takeover targets in the wake of the Chicago Mercantile's $11.3 billion purchase of the Board of Trade, a deal that created the world's largest futures exchange.

Nymex has held acquisition talks with exchanges such as NYSE Euronext and the Chicago Mercantile, people familiar with the discussions said last month. Atlanta-based Intercontinental ``may end up being more of a target now,'' Will Vicars, managing director at Sydney-based hedge fund Caledonia Investments Ltd., the Board of Trade's largest shareholder, said July 10.

Higher Winnipeg Bid?

Intercontinental spokeswoman Kelly Loeffler, Nymex spokeswoman Anu Ahluwalia and Will Hill, senior vice president of the Winnipeg exchange, declined to comment.

Intercontinental is likely to increase its offer for the Winnipeg exchange, according to the person.

Computer-based trading is fueling acquisitions by making it easier for investors to buy and sell bonds, stocks, derivatives and commodities at a single location. Global futures and options trading rose 11 percent in the first two months of the year, compared with the same period a year earlier, according to the Futures Industry Association.

Intercontinental's agreement to buy the Winnipeg exchange, announced last month, allows Winnipeg to accept a better offer if it pays a $1.15 million breakup fee, according to Winnipeg, Canada-based WCE Holdings.

The privately held Winnipeg exchange, Canada's only agricultural futures and options marketplace, grew out of a grain exchange founded in 1887. Intercontinental's Chief Executive Officer Jeff Sprecher has said adding the Winnipeg exchange will bolster its agricultural products.

Canadian Expansion

In January, Intercontinental bought the New York Board of Trade, which has sugar, coffee and cotton futures, for $1.8 billion.

Both Intercontinental and Nymex are seeking to expand into Canada to boost business.

In February, Nymex said it will acquire a 10 percent equity stake in Canada's Montreal Exchange Inc.

Intercontinental has an agreement with a subsidiary of the Toronto Stock Exchange, the Natural Gas Exchange, to offer contracts for physically delivered Canadian natural gas and electricity on its electronic trading platform through an alliance.

Shares of Nymex fell $2.83, or 2 percent, to $137.24 in New York Stock Exchange composite trading. Intercontinental dropped $3.92, or 2.4 percent, to $162.93.

To contact the reporter on this story: Matthew Leising in New York at mleising@bloomberg.net.

Last Updated: July 18, 2007 16:13 EDT