CME Group's $8.4 billion takeover of the New York Mercantile Exchange looks likely to close after executives of the Chicago futures giant won over two influential Nymex members. Robert Sahn and Gary Glass issued a letter to fellow Nymex members yesterday afternoon urging them to support the merger at Monday's shareholder meeting after coming out against the deal earlier this week. The duo, along with veteran Nymex member Mark Fisher, believe the transaction was poorly negotiated by Nymex management and had threatened to derail the merger if CME didn't increase its offer. The latest tirade came after CME disclosed that a special $750,000 payout to each Nymex member could be taxed at a higher rate than originally expected. But CME chief Craig Donohue persuaded Sahn to support the deal after flying by helicopter from Manhattan to East Hampton Wednesday night.