TWA said it would move out of Manhattan.

The relocation of its world headquarters to Mount Kisco in Westchester County will be completed by the end of next year, the company said. Separately, Shearson Lehman Bros. announced that it will expand its New York headquarters with a $470-million building, creating 1,500 new jobs and retaining 4,900. TWA’s announcement followed an earlier one last week by Montgomery Ward & Co., which said it would close its New York office and consolidate its Chicago headquarters.