Canada said it will consider purchasing fighter aircraft other than Lockheed Martins F-35 jet, after an external report showed the cost of the plane would be as much as $45.7 billion over 42 years.The report by KPMG follows concerns expressed by lawmakers about the escalating cost of the F-35. In the U.S., the program to buy a planned inventory of 2,443 fighters for the Air Force, Navy and Marine Corps is now estimated to cost $395.7 billion, 70 percent more than when Lockheed Martin won the contract in late 2001. Its the Pentagons costliest weapons system.The decision today means the Canadian government may consider alternatives to the F-35, which could include Boeings F-18 Super Hornet and Eurofighters Typhoon. The F-35 is being developed and built in west Fort Worth.Prime Minister Stephen Harpers government was criticized in April by the countrys auditor general for mismanaging the F-35 purchase, prompting it to set up a secretariat within the public works department to coordinate the acquisition of new fighter jets.The Department of National Defence was "too involved" with the development of the F-35 program to run a fair competition for new fighter jets, Auditor General Michael Ferguson said in an April 3 report. Defense officials didnt provide complete cost information to members of the nations parliament or fully inform decision makers about the risks of buying the jets, the report found.Canada has been involved with Lockheeds Joint Strike Fighter program since 1997. Canada signed memorandums of understanding to participate in the program in 1997, 2002 and 2006.The government announced in July 2010 that it would buy 65 F-35s to replace the countrys aging fleet of CF-18 Hornet jets.The projects budget was set at $25 billion in Canadian dollars over 20 years in 2008, including $9 billion to buy the jets and $16 billion to operate and maintain them.Canada was one of eight partner nations in the F-35s development program and committed to buy the plane, but has become increasingly concerned about rising costs. Canada hosted a meeting of the partners in Washington in March to discuss concerns after Italy decided to cut its orders by a third.