The failure of Mitsubishi Heavy Industries Ltd. to acquire the energy-system assets of France's Alstom SA has put the Japanese engineering group at the risk of falling far behind U.S. rival General Electric Co.

"It will be troubling for us if GE wins (the bid for Alstom). It's a great threat," a senior Mitsubishi Heavy official said earlier this month.

The concern became reality over the weekend when the Alstom board decided to continue to support GE's offer, which had earlier met calls for revision from the French government. Paris eventually gave the green light to the $16.9 billion offer to buy most of the French industrial group's energy business.