Boeing [NYSE: BA] and 777 Partners have announced the Miami-based investment firm will nearly double its 737 MAX order book with the purchase of 30 additional jets. The new order expands 777 Partners’ commercial aircraft portfolio to a total of 68 737 MAX’s, in its fourth order this year for the fuel-efficient, single-aisle jets. Valued at $3.7 billion at list prices, the order will enable 777 Partners to expand 737 MAX operations across the fleet of its affiliated global low-cost carriers.

The 737 MAX family reduces fuel use and carbon emissions by at least 14% compared to the airplanes it replaces, reducing operating costs as well as the environmental footprint for 777 Partners’ affiliated airlines. Every 737 MAX features a passenger-pleasing Boeing Sky Interior, highlighted by modern sculpted sidewalls and window reveals, LED lighting that enhances the sense of spaciousness and larger pivoting overhead storage bins.

777 Partners is a Miami-based private alternative investment firm that invests across a number of high growth attractive verticals. Founded in 2015, 777 Partners initially applied its expertise in underwriting and financing of esoteric assets to diversify across a broad spectrum of financial services businesses, asset originators, and financial technology/service providers. In recent years, the firm has broadened its mandate and now invests across six different industries: insurance, consumer and commercial finance, litigation finance, direct lending, media and entertainment, and aviation.