Bombardier's CSeries commercial aircraft has been certified by Canada's transportation regulator, after years of delays and cost overruns.

The Montreal-based manufacturer held a news conference Friday morning in Mirabel to provide an update on the 110- to 125-seat CS100, the smaller of two planes in the $5.4-billion US CSeries program.

Quebec Premier Philippe Couillard confirmed to CBC News ahead of the event that the certification for the jet would be announced.

"We should all be very proud of this," said Couillard. "When was the last time a Canadian airliner was certified in our history, and it's done in Quebec. It's a significant part of our economic future."

Federal Transport Minister Marc Garneau, a former astronaut, was on hand to make the announcement.

"This is a big day," Garneau said, adding that certification sends a strong message to investors and potential customers that Bombardier's CSeries — the largest jets the company has ever made — is open for business.

Ottawa has given its OK to the smaller, 110-seat version of the plane, known as the CS100. A larger model, the CS300, is expected to be certified within six months.

Last month, the Quebec government bailed out the aerospace giant, so the province has a direct stake in any future success of the project. That came on the same day the company announced a $3.2-billion writedown on the project which has seen many delays and cost overruns.

The federal government said it is reviewing an application to match the province's investment in the company and the project.

Other government officials, including Quebec's Industry Minister Jacques Daoust, were on hand for the ceremony.

Bombardier has said it expected to get the green light on certification by the end of the year.

Commercial flights next year

The last large media gathering at the CSeries assembly facility north of Montreal was in February for the first flight of the larger CS300, which is expected to see its first deliveries in September.

Since the first test flight in September 2013, CSeries jets have undergone more than 1,000 test flights. The company claims the jets are much quieter than current long-haul jets, and up to 20 per cent more fuel efficient.

Bombardier has received 243 firm orders for both models of the plane. The CS100 is expected to enter into service with Lufthansa by mid-2016, several months ahead of the CS300.