Exeter have exercised a clause in the 26-year-old's existing contract to keep him at Sandy Park until at least 2021.

Any player with fewer than 60 caps has to return to Wales when their contracts expire to remain eligible for Wales.

As 40-cap Francis has had a clause enacted in his current deal rather than a new deal, the rule does not apply.

"When he initially signed his last contract there was a clause within that contract which stated his contract could be extended with us as long as various things were met. That's what's been the case," Exeter director of rugby Rob Baxter told BBC Sport.

"Tom's not come off contract, it's just been a very easy extension because both he wanted to stay and we wanted to keep him and we both fulfilled obligations that lengthened the extent of his contract."

British and Irish Lions players Rhys Webb and Alex Cuthbert have been ineligible to play for Wales since summer moves to Toulon and Exeter respectively as they had failed to meet the 60-cap quota, which came into force in November 2017.

Francis, who moved to Exeter from London Scottish in 2014, signed his current deal in July 2016.

"We probably had some hints that there was going to be a potential issue arising with Wales," Baxter added.

"Because of that we put various things in the contract that meant he's not put in that awkward position where he's turning down a contract in Wales, because effectively his contract's just taken on the extension period.

"He's enjoying being here, he's playing some good rugby, he's played in some huge games for us and has also had a huge Six Nations for Wales which is fantastic for him."