NEW YORK - United Airlines said Wednesday it plans to lay off up to 16,000 workers starting in October amid a prolonged industry downturn due to the coronavirus.

The big US carrier, which had previously said as many as 36,000 workers could be terminated, said early retirement and other programs had lessened the need for even deeper cuts, but the "devastating" impact of Covid-19 on airline travel still required layoffs.

Even with those voluntary programs and other cost-cutting, the savings "have not been enough to avoid involuntary furloughs entirely," the company said.

"Today, each of our operations leaders communicated directly with their teams to share the heart-wrenching news that approximately 16,000 United employees will be notified of an involuntary furlough effective as early as October 1."

The cuts affect nearly 7,000 flight attendants and almost 3,000 pilots, among other staff.

"The pandemic has drawn us in deeper and lasted longer than almost any expert predicted, and in an environment where travel demand is so depressed, United cannot continue with staffing levels that significantly exceed the schedule we fly," the company said.

"Sadly, we don't expect demand to return to anything resembling normal until there is a widely available treatment or vaccine."

United was among the airlines that received federal funding under the federal Cares Act, which barred involuntary staff cuts through the end of September.

United said it was working with its unions to press the government to provide another emergency aid package with an extension of payroll support for airline workers. However, that bill remains stuck in a partisan fight in Washington.