The U.K.-based TUI Travel company has announced a commitment to purchase 60 narrow-bodied Boeing 737 jets.

The company said Friday it also has the option and right to buy another 90 Boeing 737s.

The holiday company says the current list price for the 60 jets is about $6.1 billion (4 billion pounds), but it says it obtained significant discounts.

Delivery is expected to begin in January 2018 and continue until March 2023.

The company says the new planes will be powered by LEAP-1B engines made by CFM International.

The proposal is subject to shareholder approval.