By Pratyush Thakur and Mike Stone

(Reuters) -Defense contractor Lockheed Martin lifted its annual profit and sales forecasts on Tuesday, but shares slid 5% because the company's F-35 fighter jet program faced payment headwinds stemming from the government contracting process.

The Bethesda, Maryland-based company now expects per-share profit of $26.65 for 2024, above its earlier forecast of $26.10 to $26.60.

Still, shares slid 5.2% in early trading in New York to $582.71.

Lockheed's flagship F-35 program has been facing challenges, particularly due to delays in rolling out an upgrade intended to enhance the fighter jet's processing capabilities.

But drawn-out contract negotiations have meant Lockheed is having to incur procurement costs for the F-35 jets in lots 18 and 19, set to be delivered in 2026 and 2027.

The absence of a contract means Lockheed is having to pay suppliers for long-lead materials such as sensors, radars and other electronics for the jets without being reimbursed by the government. This impacted sales and profit at both the business and company level.

"Had the program been fully funded over this period of time in the third quarter, we would have had sales closer to about 5% growth." Jay Malave, Lockheed's CFO, told Reuters in an interview.

He added that in the quarter, the company's "profit was up 3% and that would have similarly - with the F-35 impact on that lot 18-19 negotiation - would have otherwise been up 7%." Malave told Reuters the company's boosted annual guidance year anticipated a finalized contract by December 31.

An initial "handshake" deal on a contract is expected next month, a person familiar with the negotiations said on condition of anonymity.

The business that makes the F-35 jet posted a 3% decline in sales in the third quarter. Lockheed's overall revenue of $17.10 billion missed analysts' estimates of $17.35 billion, according to LSEG data.

Lockheed also sees full-year sales of $71.25 billion, slightly above the midpoint of its earlier forecast of $70.50 billion to $71.50 billion.

Conflicts in the Middle East and the protracted Russia-Ukraine war have resulted in nations boosting defense spending, which has benefited arms manufacturers.

Lockheed's per-share profit stood at $6.80, beating expectations of $6.50.

(Reporting by Pratyush Thakur in Bengaluru; Editing by Shinjini Ganguli and Nick Zieminski)