ATHENS, Greece — Greece's dominant Aegean Airlines has signed a preliminary agreement with Pratt & Whitney to buy new fuel-efficient and lower-pollution engines for up to 62 new passenger jets.

The memorandum of understanding signed in Athens Wednesday is worth up to $1.5 billion, and is part of the 5-billion-euro ($5.7 billion) agreement announced in the summer for Aegean to buy new Airbus A320 neo planes.

The Pratt & Whitney GTF engines are designed to offer at least 16 percent better fuel efficiency and 75 percent noise reduction, as well as significantly lower pollution emissions, according to Aegean.

The memorandum of understanding will also provide for long-term maintenance for the new engines.

Aegean was founded 19 years ago and serves 150 destinations in 44 countries.