CHICAGO, July 19 (UPI) -- Futures exchange giant CME Group Inc. (NYSE:CME) says it has upped its per-seat offer in a bid to purchase the New York Mercantile Exchange.

CME, owner of the Chicago Mercantile Exchange and the Chicago Board of Trade, announced its intentions of purchasing Nymex Holdings Inc. (NYSE:NMX) in March, and has since raised its offer for the New York exchange's membership seats from $612,000 to $750,000, the Chicago Sun Times reported Saturday.

Analysts say the deal is worth more than $6 billion and also includes an offer to Nymex's shareholders of $36 per share in cash and one-tenth of a share of CME Group stock for every Nymex share held. The newspaper said CME Chief Executive Craig Donohue is working to smooth over opposition to the deal among some Nymex members, who believe they should be getting a richer offer in light of a recent tumble in CME Group's stock price.

"It's the back door to try to get a deal done," Justin Lumiere, a New York-based analyst at brokerage ICAP, told the Sun-Times. "There is a higher probability now that the vote will go through, now that they've increased the seat consideration. But this is not a slam-dunk."

Yahoo moves to sell Asian subsidiary

TOKYO, July 19 (UPI) -- Yahoo Inc. (NASDAQ:YHOO)'s chief executive says he's considering selling the Internet search engine's stake in its Japan-based subsidiary.

In a letter sent to shareholders Thursday, Yahoo CEO Jerry Yang says the company is seeking to maximize its value in the face of a proxy battle with an alliance between Microsoft Inc. and billionaire investor Carl Icahn, the Japanese Kyodo News agency reported Saturday.

"Your board takes seriously its obligation to examine all value-creating steps it could take and continues to actively examine many of these now, including a potential spinoff of our Asia assets and a return of cash to stockholders," Yang and Yahoo board chairman Roy Bostock said in the letter, an apparent reference to Yahoo's 33 percent stake in Alibaba.com.

Yahoo's shareholders will meet Aug. 1 to vote on a bid by Microsoft, the Internet's third-largest search engine operator, to replace the board of Yahoo, the No. 2 search engine. Microsoft has allied itself with Icahn in an effort to forge a strong competitor to Google Inc. (NASDAQ:GOOG)'s dominance of the Internet search engine field, Kyodo said.

United hires airliner cleanliness expert

CHICAGO, July 19 (UPI) -- United Airlines says it has hired an executive with a track record of sprucing up the tired look of Delta Airlines' worn airliner interiors.

United, based in Chicago, has hired Timothy Canavan to fill the newly created role of vice president of maintenance and aircraft appearance, the Chicago Tribune reported Saturday. In that position he'll report to another former Delta exec, Joe Kolshak, who joined United last month as senior vice president of operations.

The newspaper said Canavan's 22-year career at Delta included an initiative to clean up the passenger compartments of its airline fleet, whose griminess had generated passenger complaints.

Verizon, Chicago Transit ink subway deal

CHICAGO, July 19 (UPI) -- Chicago Transit Authority officials say they've struck a deal with Verizon Wireless to provide cell phone service in the city's subway tunnels.

Currently, only U.S. Cellular offers service in the tunnels. But that will change to allow Verizon, which has far more customers nationwide than U.S. Cellular, to operate in the CTA tunnels as well, the Chicago Sun-Times reported Saturday.

"We are trying to move it along as quickly as we possibly can," Verizon spokeswoman Carolyn Schamberger told the newspaper.

The Sun-Times said CTA workers will be able to access Verizon's tunnel service by the end of August, but it was not known when all of Verizon's 67 million users will have the option of dialing up while underground in Chicago.