The federal government has extended the contract of Quebec-based L-3 Communications MAS to maintain its fleet of CF-18 fighter jets for up to another decade.

Prime Minister Stephen Harper sits in a CF-18 Hornet as Maj. Daniel Dionne explains the controls at the L-3 Communication plant Wednesday in Mirabel, Que. Harper says Canada's fleet of CF-18 fighter jets will have a 'useful life' for another decade but 'will not go on forever.' (Ryan Remiorz/Canadian Press)Prime Minister Stephen Harper and Defence Minister Peter MacKay made the announcement Wednesday at the company's operations in Mirabel airport.

The $467-million contract extension begins this year and runs until 2017, with a three-year extension option. The work will be completed by about 400 employees at L-3's Quebec facilities in Mirabel and Bagotville, as well as its Alberta operations in Cold Lake.

The contract guarantees another decade of "useful life" for Canada's CF-18s, but the aircraft "will not go on forever," Harper told reporters.

"Our government is committed to providing the Canadian Forces with the tools and equipment they need to defend our sovereignty at home and perform their missions abroad."

The Conservative government has agreed to purchase 65 F-35 Joint Strike fighters to replace its fleet of CF-18s at a cost of up to $18 billion.

F-35s 'a necessary purchase': PM

The Opposition Liberals have pledged to review the sole-sourced purchase if they are elected to form the next government to see whether Canadians received the best possible deal without a single competing bid.

"The priorities of this government are prisons and planes," Liberal Leader Michael Ignatieff said Wednesday. "Is this what Canadians want from their government right now, in the middle of a $54 billion deficit?"

But the prime minister noted it was a Liberal government that initially signed Canada to the F-35 project in 2002. He also emphasized the spinoff benefits from the CF-18 project and the F-35 contract to Canada's aerospace industry, much of which is based in Montreal.

"We will need this equipment at the end of the decade," he said. "So the opposition should stop playing political games with this and support this, which is a necessary purchase for all of us."

L-3 Communications MAS is the Quebec-based subsidiary of the New York-based L-3 Communications, which purchased Bombardier's military business division, Bombardier Defence Services, in 2003.

The F-35 purchase is expected to benefit nearly 100 Canadian companies and support thousands of technology jobs.