An 18-month review of Canada's fighter jet needs has concluded that the government should skip a new competition and proceed with the C$9 billion ($8.22 billion) purchase, three sources said.
The decision must still be finalized by Prime Minister Stephen Harper's cabinet and could trigger a fresh storm of criticism from opposition politicians over costs that derailed the purchase two years ago.
The United States and its allies plan to buy more than 3,100 F-35s in coming years to replace aging F-16s, F/A-18s and other warplanes.
Following is a list of the expected purchases, according to data provided by Lockheed, the prime contractor for the $398.6 billion weapons program, and defense officials in the United States and other purchasing countries.
Lockheed is developing three models of the plane for the U.S. military and eight partner countries that helped fund the plane's development - Britain, Australia, Italy, Turkey, the Netherlands, Denmark, Norway and Canada.
South Korea, Japan and Israel have also placed orders for the jet.
U.S AIR FORCE
The U.S. Air Force plans to buy a total of 1,763 F-35 conventional landing A-models through 2037.
The Air Force is training F-35 pilots and technicians at Eglin Air Force Base in Florida, and recently began night training flights at the base. More than 100 pilots have been qualified to fly the jet and more than 1,000 technicians have also been trained to service it.
The Air Force is also flying jets at bases in Nevada and Arizona.
Current plans call for the U.S. Navy to buy 260 C-model F-35s, which have longer wings and a special tailhook that allows them to land on aircraft carriers. Lockheed and the F-35 program are testing a redesigned tailhook, with at-sea testing due to take place in the fall of 2014.
U.S. MARINE CORPS
The Marine Corps, the smallest of the U.S. military branches, plans to buy 340 F-35 B-models, which can take off from shorter runways and land vertically, and 80 F-35 C-models to replace its current fleet of F/A-18 Hornets, EA-6B Prowlers, and AV-8B Harrier "jump jets."
The Marines are flying jets at an air base in Arizona, and say they are on track to start using the F-35Bs by mid-2015.
Later this month, the Marine Corps is also due to start receiving F-35 jets at an air base in Beaufort, South Carolina, where it plans to train dozens of pilots and service technicians each year.
The Royal Air Force and Royal Navy, which have invested $2 billion to help develop the new warplane, plan to buy a total of 138 F-35 B-models.
Britain has so far committed to buying 48 of the new planes, and is expected to announce plans for the next 14 jets this year. It has already received three jets.
The F-35B will make its first appearance at two air shows in Britain next month. Weather permitting, the plane will also make a brief fly-by appearance at the naming ceremony for Britain's new aircraft carrier on July 4.
Italy initially planned to buy 131 F-35 fighters, but curtailed its order to 90 jets in 2012. It is slated to buy 60 F-35A models and 30 F-35Bs.
Italy's state-owned defense company Finmeccanica is one of the subcontractors on the project and its Alenia unit will assemble the planes purchased by Italy and the Netherlands at a large facility in northern Italy.
The Dutch military initially planned to buy 85 F-35As in coming years but announced in September that it would buy just 37 jets for now, and could order more later. It has already received two jets that will be used for training.
Turkey is slated to buy 100 F-35As and has placed a firm order for the first two jets.
Australia is slated to buy 100 F-35As, with the first jet to be delivered later this year. In April, Australia announced plans to buy 58 jets in addition to the 14 already ordered.
Norway plans to buy 52 F-35A fighter jets and has authorized the purchase of 16 jets.
Denmark was slated to buy 30 F-35As, but it has launched a fresh competition that will not be decided until the end of June 2015.
Canada was poised to buy 65 F-35As for C$9 billion but announced in December 2012 that it would evaluate all available options for new fighters. This followed an outcry over the government's decision to buy the F-35 without an open competition.
Canada is expected to formally decide in June whether to proceed with its planned F-35 purchase.
Israel has ordered 19 F-35 jets and plans to order up to 75 jets in coming years. A second order could come later this year.
Japan announced in December 2011 that it was ordering 42 F-35 A-model jets and may order more in coming years. Japan is also building a final assembly and checkout plant for the jets.
South Korea has confirmed its plans to buy 40 F-35A jets to replacing its aging F-4 jets.
Singapore and Belgium are among other countries that have expressed interest in the Lockheed fighter jet. (Editing by Ross Colvin)