In October, chief executive Neil Bruce succeeded Robert Card, an outsider brought in after the Montreal firm faced allegations of corruption against former executives.
Bruce said on a conference call the company would invest C$50 million on a sweeping cost-cutting program that would use strategies like consolidating office space and evaluating how much staff SNC needs to execute its work.
Bruce did not explicitly announce layoffs.
"It's more of an efficiency program," Bruce told analysts.
"If we become far more efficient and we win more work then we will provide more opportunities for our talented individuals to go with us," he said.
SNC-Lavalin said its 2015 profit would be at the lower end of its previously announced range of C$1.30-C$1.60 per share.
Revenue rose 21 percent to C$2.43 billion ($1.84 billion) in the third quarter ended Sept. 30, helped by the acquisition of British resource-sector engineering group Kentz Corp last year.
Analysts on average had estimated revenue of C$2.39 billion.
Net income attributable to shareholders rose nearly fourfold to C$224.2 million in the quarter, mainly helped by a net gain of C$145.7 million from the sale of its stake in the Ambatovy Nickel project in Madagascar in September.
On an adjusted basis, earnings were 78 Canadian cents per share, above the average analyst estimate of 50 Canadian cents, according to Thomson Reuters I/B/E/S.
(Reporting by Allison Lampert in Montreal and Sneha Banerjee in Bengaluru; Editing by Sriraj Kalluvila and Phil Berlowitz)