July 11 (Reuters) - Deliveries of F-35 jet are set to

resume shortly without the complete TR-3 software upgrade, the

head of the F-35 Joint Program Office (JPO) said on Thursday.

The delays in delivery to the Pentagon were linked to the

lingering issue on the TR-3 tech refresh, which refers to a

series of software improvements to the F-35 for better displays,

computer memory and processing power.

The decision to move forward without complete implementation

of the TR-3 software was made in coordination with the various

stakeholders, according to the JPO.

"We made the decision to move forward with the truncation

plan for TR-3 software," said Lt. Gen. Mike Schmidt, program

executive officer at the F-35 Joint Program Office.

Lockheed Martin ( LMT ), manufacturer of these aircraft, was

left with F-35 jets in its inventory as a result of the delays.

Advanced fighter jet contributes 27% of total consolidated net

sales of the company.

During an investor call, Lockheed CEO Jim Taiclet had said

that delivery of the first TR-3 combat training-capable aircraft

was expected in the third quarter, with a full transition to

combat-capable aircraft expected by 2025.