London, June 29  :  Actress Jennifer Aniston and boyfriend Justin Theroux boarded a private jet with George Clooney and his girlfriend Stacy Keibler.

All four got on the aircraft in Switzerland Wednesday, reports tmz.com. Their destination is not known. However, it marks significant progress in the friendship of screen stars Aniston and Clooney.

Clooney is famously close to Aniston's ex-husband Brad Pitt.

And this comes after Clooney and Pitt enjoyed dinner and drinks together at an Italian restaurant in Berkshire, England.

Aniston and Clooney have not been spotted with each other for years.

© IANS