One analyst says that Shaw's sale of its energy and chemicals business to Technip earlier this year, which is set to close by next March, made the link with CB&I "easier to consummate." Shaw also is selling its nuclear sector investment in Westinghouse.

"I think the biggest risk to CBI is the end-market expansion into the power sector," says Fisher. "Any time you have end market expansion combined with fixed price contracts you have risk. I wouldn't be terribly surprised if CBI sold off some of the services assets - perhaps environmental and infrastructure - that were acquired in this deal."