U.S. private equity firms Siris Capital and Evergreen Coast Capital affiliates have agreed to acquire UK travel commerce platform Travelport Worldwide Ltd for about $4.4 billion in cash.

Evergreen and Siris will acquire Travelport for $15.75 per share, a 2.3 percent premium to Travelport closing price on Friday.

The acquisition is expected to be completed in the second quarter of 2019.

Travelport generates revenue of $2.5 billion annually.