June 27 (Reuters) - The New Terminal One (NTO), a consortium of labor, operating and financial partners at New York's John F. Kennedy International Airport, said on Thursday it issued $2.55 billion in green bonds, the largest-ever municipal bond financing for an airport project.

It is the second time JFK's NTO issued bonds in less than a year to refinance about $6.63 billion in bank loans. The consortium first sold $2 billion in bonds in December.

NTO said it initially offered $1.5 billion of Series 2024 Special Facilities Revenue Bonds, but increased the issuance due to investor demand. The consortium received orders for $6 billion, a source familiar with the matter told Reuters on Wednesday.

"We were very pleased with the investor demands...it reinforces the very strong value proposition of the New Terminal One at JFK," said NTO CEO Jennifer Aument.

Construction of the new international terminal on the site of JFK's current Terminals One, Two and Three at one of the world's busiest airports is about 40% complete, backed by a consortium of financial, operating, and labor partners -- Ferrovial, JLC Infrastructure, Ullico and Carlyle .

NTO has reached agreements with eight major airlines for the new international terminal, scheduled to open in 2026, following a $9.5 billion first phase of a major transformation project.

When fully completed, the new terminal is expected to handle more than 16 million passengers a year by 2030, about three times the number handled by the existing Terminal 1 in 2023.

The interest in the market decreased slightly for the latest bond issue compared with bonds issued in December, which were oversubscribed by 7.7 times even after increasing the transaction by $500 million to $2 billion.

"We were still three times oversubscribed, which is exactly where you want to see in a good bond deal," NTO's CFO, Manoj Patel, said. Some of the investors that had bought bonds in the first issue returned to invest in the latest bond issue, he said.

The bonds were designated as Green Bonds by Kestrel Verifiers, an independent second-party opinion provider that confirmed the uses of the bonds conform with Green Bond principles, which seek to support issuers in financing environmentally sound and sustainable projects.

Spanish infrastructure giant Ferrovial is the lead investor with a 49% stake in the new terminal consortium as part of its strategy to focus on the U.S. market. (Reporting by Corina Pons; additional reporting by Doyinsola Oladipo in New York; Editing by Leslie Adler)