LIMESTONE — A plan for a Chinese-owned rail car factory at the site of the former Loring Air Force Base has been delayed because a top company official has been unable to get a visa to come to the U.S. and work on the project.

The Portland Press Herald reports Sui Ping has been trying to get the work visa since spring. Loring Development Authority CEO Carl Flora says the agency is continuing to work with a company that builds rail cars in China on locating a manufacturing facility in Maine.

Flora says he’s not sure what’s holding up the visa. The state’s congressional offices have been contacted for help.

The company, NORINCO, hasn’t committed to Loring, but Flora and Sui have signed a preliminary agreement to work toward that goal.