Continuing to broaden its portfolio of products, Armstrong World Industries said Friday it has agreed to acquire a Los Angeles-based maker of architectural specialty metal ceilings and felt walls, partitions and facades.

Lancaster-based Armstrong said it will pay $121 million in cash and stock for Arktura LLC, which has annual revenue of $37 million and 150 employees. Armstrong described Arktura as a company that fuses “ingenuity and creativity with leading edge technologies and software to deliver visionary design.”

The transaction is expected to be completed by year-end.

Armstrong and Arktura also plan to launch Arktura Ventures LLC, an incubator for exploring and accelerating new product, technology and materials solutions in architecture, design, engineering and construction beyond their existing core businesses.

The acquisition will be the eighth by Armstrong, the nation’s largest ceilings manufacturer, since spinning off its floor division in April 2016 into an independent company. The transaction also is its third this year alone.