The deal, worth $3.9 billion at list prices, increases the GECAS fleet of 737s either delivered or on backlog to 482 aircraft.
The GECAS order book now includes 387 737NGs and 95 737 Max aircraft.
The influential lessor increased its order book because it sees demand continuing to grow for more fuel-efficient aircraft, says Norman Liu, president and chief executive of GECAS, in a statement.
Boeing says the deal reinforces how the 737 series is valued in the leasing market.
Both the 737NG and the 737 Max are powered exclusively by CFM International engines.
As the deal was previously announced, the 737 Max order book still stands at 1,763 aircraft.
(Stephen Trimble - Flight Global News)