SNC-Lavalin Group Inc. warns its 2019 results could be significantly lower than anticipated, largely due to cost overruns at some construction projects and says it will undergo a reorganization to exit or section off its poorer performing segments.

The Montreal-based engineering giant is withdrawing all previous financial guidance for 2019, due largely to project cost adjustments in its resources and infrastructure segments.

It will also book an additional $1.9 billion in impairment charges related to its oil and gas division.

SNC shares fell seven per cent to $23.73 in morning trading on the Toronto Stock Exchange.

The company says it will undergo a reorganization of those financially troubled parts of the business, as part of the company's broader efforts to de-risk and generate more consistent earnings.

The Montreal-based engineering giant announced that it is exiting lump-sum turnkey contracting and will reorganize the company's resources segments and infrastructure construction segments into a separate business line following "continued poor performance."