WASHINGTON (Reuters) - The U.S. Defense Department plans to buy 404 Lockheed Martin Corp LMT.N F-35 fighter jets over the next five years, a net decrease of 5 to 7 percent from last year's plan, sources familiar with the plans said on Friday.

A Lockheed Martin F-35 Lightning II fighter jet is seen in its hanger at Patuxent River Naval Air Station in Maryland October 28, 2015. REUTERS/Gary Cameron

The orders will amount to about $40 billion in new revenue for Lockheed, the Pentagon's No. 1 supplier, and engine maker Pratt & Whitney, a unit of United Technologies Corp UTX.N.

The revised procurement numbers will be released on Tuesday when the Pentagon issues its fiscal 2017 budget and the new five-year plan, said the sources, who were not authorized to speak publicly before the budget release.

The change in the Pentagon’s plan for the $391 billion weapons program defers orders for 45 Air Force jets, compared with last year’s plan, while accelerating orders for the Navy and Marine Corps models of the aircraft, the sources said.

The Pentagon still plans to buy a total of 2,457 jets for all three military services in coming years, they added.

The Pentagon’s plan does not include an estimated 260 international F-35 orders over the five-year period, said the sources. Those orders could rise further over the period given potential orders from countries including Finland, Denmark, Belgium and Singapore, the sources said.

The new plan calls for the Air Force to buy 243 F-35 jets through fiscal 2021, 45 fewer than planned, as the service juggles funds to pay for a new long-range bomber to be built by Northrop Grumman Corp NOC.N, and KC-46A refueling planes to be built by Boeing Co BA.N.

It calls for the Navy and Marine Corps to buy 64 F-35C jets, which can take off and land on aircraft carriers, over the next five years, and 97 F-35B jets, which can land like a helicopter, the sources said.

Defense Secretary Ash Carter this week announced plans to buy 13 more F-35 fighter jets for the Navy and Marine Corps than planned last year, but he did not disclose the total number of jets to be purchased across the department.

Two sources said the plans could actually represent an increase of 21 F-35 jets for the Navy and Marine Corps over the five-year period. No comment was immediately available on the discrepancy from Carter’s office.

The U.S. Marine Corps declared an initial squadron of 10 of its F-35B model jets ready for combat last July.

The Air Force is due to follow suit in August, followed by the Navy in late 2018 or early 2019.