WINNIPEG, Manitoba, Nov 29 (Reuters) - Alberta's Capital Power is not planning to build new natural gas-fired power plants in Canada as Prime Minister Justin Trudeau's proposed electricity regulations to fight climate change make new investments in such facilities unviable, CEO Avik Dey said.

The concerns raised by Capital, Alberta's second-biggest power generator, mirror those of Alberta Premier Danielle Smith, who on Monday said the province would defy the federal government's proposed clean electricity regulations (CER). Ottawa's regulations aim to eliminate emissions on a net basis from the country's power grid by 2035.

"Am I looking at building new capacity? The answer is no, today, because of the ambiguity of the CER," Dey told Reuters, adding the company has no plans to buy any Canadian plants either.

The CER in its current form doesn't justify investment in a new gas-fired plant meant to operate 30 years, he said.

Capital Power's previously unreported position on new plants underscores how the Trudeau Liberal government's draft power regulations risk curtailing investment in a grid that Ottawa expects to face growing demand as more Canadians buy electric cars.

Unlike other provinces with hydro or nuclear power, Alberta burns high-emitting natural gas to produce most of its electricity. Smith has warned the regulations would lead to grid brownouts and blackouts, a scenario that Dey said he sees as well. (Reporting by Rod Nickel in Winnipeg, Manitoba; additional reporting by Steve Scherer in Ottawa Editing by Denny Thomas and Chizu Nomiyama)