UPDATE 1-Brazil's Gol signs $600 mln Castlelake deal for new Boeing aircraft

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SAO PAULO, Jan 24 (Reuters) - Brazilian airline Gol said on Monday it has signed a deal with U.S. private equity firm Castlelake LP to get up to $600 million in financing to purchase new Boeing 737 Max 8 aircraft.

Gol Linhas Aereas Inteligentes SA, as the company is formally known, said in a securities filing the deal includes 10 finance leases and two sale-leasebacks. The new aircraft are expected to be delivered from this month, it added.

The interest rate for the finance leases is seen at about 6% per year, according to Gol, which it said is lower than the operating lease costs of its current fleet.

The deal will also provide resources for Gol to return some of its Boeing 737 NG aircraft, it said.

"The company expects to return up to 18 737 NG aircraft in 2022 and a total of 34 NG aircraft by year-end 2025," Gol said. (Reporting by Gabriel Araujo; Editing by Jason Neely and Jan Harvey)