WASHINGTON — Lockheed Martin is getting closer to signing on Singapore as a cuustomer for its F-16V upgrade package, with an agreement potentially coming before the end of 2015. onas a customer for its F-16V upgrade package, with an agreement potentially coming before the end of 2015.

Meanwhile, the company continues to work other opportunities for F-16 upgrades in the Pacific, including a likely sale in South Korea.

Rod McLean, the head of Lockheed Martin's F-22/F-16 integrated fighter group, told Defense News last month that the company is closing in on a new customer for the F-16V package in the Pacific region.

"We should probably announce something by, certainly the end of the year, if not earlier, on an upgrade opportunity there," McLean said. "Our other customer doesn't care to have their name mentioned a lot in media. It's in Southeast Asia, I'll say that."

A source with knowledge of the discussions told Defense News that McLean was referring to Singapore, and that the agreement to upgrade Singapore's fleet of F-16s was "basically a done deal."

Singapore operates 60 of the F-16C/D block 52 configuration. The F-16V upgrade adds an active electronically scanned array radar, along with upgraded mission computer and cockpit enhancements. Taiwan is the first customer for the upgrade package.

There had been was some question about whether Lockheed could do the F-16V upgrade package for Singapore, as that fleet has been was upgraded with Israeli electronic warfare systems that would need to be modified to work with Lockheed's upgrade package. However, the source said "it sounds like they have found a solution to the problem" and indicated that is no longer a hurdle to negotiations.

The source added that Lockheed is making a major marketing push in both Thailand and Indonesia to upgrade those F-16 fleets. The Thais have over 50 F-16A/B models, while Indonesia operates 36 F-16s, many of which were purchased second-hand.

Lockheed is also continuing to push for a contract to upgrade South Korea's F-16s, an opportunity that opened up last fall after Korean acquisition officials canceled a $1.7 billion upgrade agreement with BAE.

The source said Lockheed has submitted its bid for the Korean upgrades and it is being looked at by South Korean military officials.

McLean said he was "glad to have the opportunity to support them after the cancellation of the [BAE] contract."

"We're in discussions to finalize that program. Those discussions are ongoing," he added. "There have been positives to date. I think we can certainly support their needs. I know they are having some budget reviews internally in the Korean Air Force … if they can preserve the funds we feel we should be able to support an upgrade program for them."

Twitter: @AaronMehta