Sony Corp. says it will shut down a CD manufacturing plant in the United States by the end of March and its 310 workers will be laid off. Sony spokeswoman Mami Imada said Tuesday the plant closure in New Jersey was due to declining CD sales as more people opt to buy music digitally.

After the closure of the New Jersey factory, the Indiana plant will become Sony’s only CD manufacturing plant in the United States.

Sony is hoping to expand its global presence in the digital music market dominated by Apple Inc.