Intercontinental Exchange Inc., which handles 45% of global oil futures trading, made an unsolicited $9.9 billion bid for the Chicago Board of Trade to block a purchase by Chicago Mercantile Exchange Holdings Inc.

Intercontinental offered 1.42 shares for each CBOT Holdings Inc. share, valuing the company at $187.34 a share or 13% above yesterday’s closing price. Chicago Mercantile’s cash and stock purchase, agreed upon in October, was worth $8.9 billion or $169.53 a share as of yesterday.

Intercontinental Exchange, established in 2000, and CBOT, founded in 1848, together would trade oil, gas, cocoa, coffee, orange juice, gold, and financial futures and options based on Treasuries, stocks and interest rates. They would control a wider range of contracts than any other derivatives exchange.

“This is the industry upstart making an aggressive move for the granddaddy of all futures exchanges,” a professor at the London Business School who tracks exchanges, Bruce Weber, said. “It’s a very bold move.”

Commodity exchanges have surged in value, helped by growing hedge fund interest in trading energy, metals, and other commodities and by speculation that there will be more mergers. Worldwide, exchanges have announced acquisitions or joint ventures worth more than $60 billion since the beginning of 2005, according to data compiled by Bloomberg.

CBOT shares jumped 17% to $194.95 at 4 p.m. in New York Stock Exchange composite trading. They have more than tripled since an initial share sale in October 2005. Shares of Intercontinental fell $3.83, or 2.9%, to $128.10, and Chicago Mercantile fell $31,09, or 5.5%, to $532.88.

“We believe our merger is very attractive for shareholders and customers and provides substantial benefits because of the nature of our businesses,” Chicago Mercantile’s Craig Donohue said yesterday at the Futures Industry Association conference in Boca Raton, Fla. He declined to comment when asked if he would consider raising his bid.

CBOT said in a statement it would study Intercontinental Exchange’s offer and would have no comment until the review was complete.

The chief executive officer of Intercontinental, Jeffrey Sprecher, has built his company in just seven years from a startup established to compete with Enron Corp.’s electronic power and gas trading. In 2001, he acquired London’s International Petroleum Exchange, home of Brent crude oil futures. In January he completed the $1.8 billion purchase of the New York Board of Trade, gaining contracts in coffee, cocoa, and sugar.