Teneo Strategy and Sard Verbinnen & Co. work the $18B "merger of equals" between Britain's Willis Group Holdings and Towers Watson of Arlington.

willisDominic Casserley, Willis CEO, said the merger in a single stroke "fast-tracks each company's growth strategy and offers a truly compelling value proposition to our clients."

Willis shareholders will own 50.1 percent of Willis Towers Watson, which will generate a combined $8.2B in revenues from re/insurance broking, human resources consulting and risk management.

WTW will serve more than 80 percent of the global top-1,000 companies.

The Wall Street Journal today cast doubt on the merger of equals positioning. It noted that TW shareholders would receive a package of shares and special dividends worth $125.13 compared to the stock's June 29 closing of $137.98.

TW's shares are now trading at $129.74.

Teneo handles Willis, while Sard Verbinnen represents TW.