Shareholders wrap up voting on Monday on a merger deal that would combine the parents of the Chicago Mercantile Exchange and Chicago Board of Trade to create the world's largest derivatives exchange.

Most analysts are predicting victory for Chicago Mercantile Exchange Holdings Inc. after the company improved its bid for a third time on Friday in an 11th hour move to quell dissent among CBOT Holdings shareholders.

A vote that looked like it might be a toss-up, given a higher competing bid for CBOT from IntercontinentalExchange Inc., now has the makings of a landslide.

CME's Chief Executive Craig Donohue said on Friday he was very, very confident the purchase of CBOT, which was first announced in mid-October, will be approved.

Caledonia Investments Pty. Ltd., the largest owner of CBOT shares, dropped its opposition to the deal after terms were approved.

Ray Cahnman, a former CBOT board member and owner of four CBOT memberships, said Caledonia's decision to vote for the deal had a huge influence on other CBOT members.

Cahnman previously opposed the CME-CBOT deal, but said he will now vote for it. Caledonia are very shrewd and very experienced, he noted.

CBOT members and shareholders and CME members have been voting for a week. The process will culminate in separate meetings on Monday afternoon.

At Friday's closing prices CME's bid was worth about $11.9 billion, including a one-time special dividend by CBOT payable upon the deal closing. ICE's bid valued CBOT at about $11.8 billion.

Shareholders of CBOT would receive 0.375 shares of CME Holdings common stock for each share of CBOT, up from 0.350 shares in the earlier agreement, pushing their stake of the combined company to about 36 percent.