Skanska said Wednesday that it had started working on an $85 million renovation of Boeing Co. facilities in Delaware County.

The contract calls for Skanska, a Swedish construction company with major U.S. operations, to renovate an existing 300,000-square-foot production facility, as well as 50,000 square feet of office space.

Skanska said it expected to complete the project by March 2019.

The news release didn't provide details on the purpose of the renovations. Boeing and Skanska officials did not immediately respond to requests for more information.