Nov 29 (Reuters) - North American pipeline company TC Energy Corp on Tuesday said it faces another big cost increase of its troubled Coastal GasLink project, as it grapples with problems attracting workers and mountainous terrain that has forced it to move pipe with ski lifts.

First announced in 2018, the 670-km (416-mile) pipeline will transport natural gas to the Shell PLC-led LNG Canada facility on the west coast of British Columbia, Canada's first LNG export terminal.

Coastal has faced several construction delays, including COVID-19 disruptions and protests from environmentalists and some First Nations.

TC Energy raised its Coastal cost estimate in July nearly 70% from the initial budget. It now further expects "a material increase" in funding requirements due to rising labor costs and shortages.

"Coastal GasLink is one of the most complex projects, certainly in my career, that I've never seen before," said Bevin Wirzba, TC's Executive Vice-President in charge of Canadian natural gas pipelines, at its investor day in Toronto.

Along with finding unusual ways to move pipe, the need for measures to control erosion in a province that has seen both mudslides and drought has added to complexity, he said.

TC said it will provide a new cost estimate for Coastal GasLink, previously pegged at C$11.2 billion ($8.27 billion), early next year. TC will increase its asset sales to pay for additional Coastal costs, Chief Financial Officer Joel Hunter said.

TC shares fell 4.5% in Toronto.

The Canadian government-owned Trans Mountain oil pipeline is also under construction in British Columbia, competing for workers.

Coastal's problems have in past caused tensions between TC and LNG Canada, but that relationship is now "extremely strong, Wirzba said. LNG Canada spokespersons could not be immediately reached.

The pipeline is 80% complete with mechanical in-service expected by the end of 2023, TC Energy said.

TC earlier this month said it plans to sell C$5 billion worth of assets to repay debts and fund new projects. Asked if TC has any assets it would not consider selling, Chief Executive Francois Poirier said there were not.

"I remember reading a book once called, 'Sacred Cows Make the Best Burgers,'" Poirier said. "There are no sacred cows."

The company expects adjusted core earnings for 2023 to be 5% to 7% higher than in 2022.

About 95% of TC's projected adjusted core earnings are under long-term take-or-pay contracts which insulate it against rising inflation and interest rates, the company said. ($1 = 1.3636 Canadian dollars) (Reporting by Rod Nickel in Winnipeg, Manitoba, Ruhi Soni and Arshreet Simgh in Bengaluru; Editing by Devika Syamnath, Marguerita Choy and Anna Driver)