SINGAPORE (AP) — An NBCUniversal executive says a "Downton Abbey" film is in the works, with production likely to begin in 2018.

Michael Edelstein, president at NBCUniversal International Studios, said the movie has been in process for some time.

"We are working on getting the script right," Edelstein said Wednesday. "And then we've got to figure out how to get the 20 casts together."

Edelstein was speaking on the sidelines of "Downton Abbey: The Exhibition," which had its world premiere in Singapore last week. It features costumes, locations and never-before seen footage from the popular TV series.

"Downton Abbey," which concluded in 2015, portrays the lives of the aristocratic Crawley family and their servants amid the backdrop of historical events as the sinking of the Titanic and World War I.