TransCanada Corp. (NYSE: TRP) is reviewing a decision by a Montana judge blocking construction of the Keystone XL pipeline, but the impact on project timing remains unclear, the company's top crude pipeline executive said Nov.13.

"We're going through the decisions, we're reviewing the deficiencies to determine how best to address the deficiencies," Paul Miller, president of liquids pipelines for the company, said at an investor day in Toronto. "At this point, it is too soon to determine what impact the ruling will have on our schedule."

Miller added that the company remains "fully committed" to the $8 billion pipeline, which would carry crude from Alberta to Steele City, Neb., where it would connect to refineries in the U.S. Midwest and Gulf Coast, as well as export terminals.

The project, in the works for a decade, was dealt a blow earlier this month when a U.S. judge in Montana blocked construction pending further environmental review.

TransCanada is still expecting a separate ruling from a Nebraska court on routing. The company had expected to start construction on the 1,180-mile (1,900-km) pipeline in 2019.

Shares of TransCanada were down 0.33% at C$51.45 in Toronto on Nov. 13.