CALGARY, Alberta (Reuters) - Pipeline company TransCanada Corp (>> TransCanada Corporation) and oil and gas producer Encana Corp (>> Encana Corporation) both said on Tuesday they were cutting jobs, joining other Canadian energy firms that have laid off staff since global oil prices slumped.

TransCanada, the backer of the controversial Keystone XL pipeline project, said it cut 185 jobs following a restructuring to lower costs for customers affected by weak oil and natural gas prices.

The country's No.2 pipeline operator said 100 full-time jobs were eliminated, while the rest were contract jobs. The Calgary-based company has about 6,000 employees.

"These positions were removed following a restructuring of the Major Projects department," TransCanada said in a statement.

The department oversees development of its largest projects, including Keystone XL and its C$12 billion Energy East line, which will take Alberta crude to Eastern Canadian refineries and an Atlantic export port.

Canadian oil and gas producers have slashed thousands of jobs as weak prices hurt profits and cash flows. TransCanada's job cuts are its first after oil prices fell by nearly half over the past year, and are intended to keep costs low in order to maintain volumes on its lines, it said.

Encana also said it was expecting some staff reductions, but attributed the cuts to changes to its organizational structure rather than low oil prices.

Spokesman Jay Averill declined to estimate how many jobs would be affected, but said it will be "nothing near" the scale of the layoffs that followed a restructuring carried out by the company at the end of 2013.

During that period, Encana reduced its staff by about 25 percent, and shifted its portfolio away from natural gas to focus more on oil.

"We're adjusting our organization to align with the well-documented and dramatic change we've experienced over the past year and a half and would likely be making these changes regardless of the commodity price," Averill added.

(Reporting by Scott Haggett; Editing by Meredith Mazzilli)

By Scott Haggett and Nia Williams

Stocks treated in this article : Encana Corporation, TransCanada Corporation