The announcement of a tie-up that had already been widely reported has come three weeks after the Italian manufacturer released the news of its entry into the prototype arena in the respective Hypercar and GTP classes of the World Endurance Championship and the IMSA SportsCar Championship.
Tuesday's statement from Lamborghini Squadra Corse, the marque's in-house motorsport department already responsible for its GT3 and Super Trofeo Huracans, offered no insight into the change to its plans outlined last summer.
Squadra Corse boss Giorgio Sanna revealed last August that Lamborghini was working to piggyback on the Porsche-led LMDh programme undertaken in collaboration with Multimatic Motorsport.
Manufacturers entering the LMDh arena have to choose between one of four licensed manufacturers - Ligier, Multimatic, ORECA and Dallara - for the supply of the spine of a car based on their forthcoming next-generation LMP2 designs.
"We are glad to announce the technical partnership with Ligier on the LMDh project," said Sanna on Tuesday's announcement.
"As in Lamborghini Squadra Corse, we have found in Magny-Cours [where Ligier is headquartered] a team of young, competent and motivated people.
"We already feel as one team and we look forward for the next challenges in front of us."
Ligier boss Jacques Nicolet stated that he is "extremely proud" to have been chosen by Lamborghini.
"A commitment to reaching determined objectives in record time is a priority for our entire staff," he said.
"Ligier is a burgeoning company, and this decision by Lamborghini honours us and confirms our strategic direction in France and the USA."
No technical details, including the configuration of its internal combustion engine, were revealed by Lamborghini as part of the Ligier announcement.
Ligier Automotive is part of Nicolet's Everspeed group of companies that also includes single-seater constructor Mygale and HP Composites, which supplies carbon-fibre components to Lamborghini for its Huracan GTE Evo and Super Trofeo racers.
Nicolet initially became a constructor by building an LMP2 chassis based on a Pescarolo design, before linking up with Ligier at the end of 2013.
The Magny-Cours based constructor had been owned by ex-Formula 1 team boss Guy Ligier, but was a continuation of renowned Formula 3 constructor Automobiles Martini rather than a descendant of his grand prix team of 1976-1996.