Former World Endurance champion Loic Duval will return to the category for the 2018/19 'superseason', having signed with LMP2 outfit TDS Racing.
Duval, 35, won the WEC title and the Le Mans 24 Hours in 2013 as part of Audi's LMP1 team.
He was left without a full-time seat in the championship when Audi ended its LMP1 programme in 2016, but did contest this year's Bahrain season finale with G-Drive in an Oreca 07 LMP2 car and was keen to secure a return to Le Mans in 2018.
The now-Audi DTM driver has now signed up for the 2018/19 campaign with TDS, partnering team regulars Francois Perrodo and Matthieu Vaxiviere.
"I am very happy to come back to the WEC and the 24 Hours of Le Mans alongside my Audi programme, and moreover I am very excited about the environment in which I will compete," Duval said.
"TDS Racing is a very professional race team, but with strong family values.
"I am looking forward to help Francois improve and be Matthieu's wingman.
"I would like to thank both of them for this great opportunity.
"I can't wait to race in the LMP2 category, which has shown some classic fights last season."
Since Audi's LMP1 exit, Duval had focused on his campaigns in the electric single-seater Formula E series and the German touring car championship DTM.
He finished 15th in the 2016-17 season of Formula E and was not retained by his Dragon team for a fourth straight campaign, his seat taken by Porsche LMP1 racer Neel Jani.
Duval's debut DTM season with Audi, meanwhile, yielded a solitary podium and 18th place overall.
Should he, as expected, retain his place in the Audi DTM line-up, he would have to miss either the 2018 season opener at Hockenheim or the six-hour WEC race at Spa.
TDS joined the WEC full-time with an Oreca 07 in 2017 after six seasons in the ELMS championship, which the team won in 2012.
It fielded an all-French line-up of Vaxiviere, Perrodo and Emmanuel Collard this year, and finished on the class podium in the Silverstone opener but did not make the top three for the rest of the campaign.
"During our 2017 WEC season, Francois and Matthieu have shown continuous improvements in LMP2 racing," said team manager Xavier Combet.
"They have consolidated their driving skills and race craft in what has proved to be an extremely competitive environment.
"Building on this experience, we have decided to go on and to take a new step by entering an LMP2 car in the 2018-19 WEC superseason.
"Teamed with Loic Duval, who has a very strong experience in endurance, this second WEC season for us promises to be very exciting."