United Airlines is offering pilots to take a month off at reduced pay, according to a union memo sent on Friday, a measure that follows flight cuts due to the spread of coronavirus.

United on Friday announced service reductions throughout Asia because of the illness, which has sickened more than 83,000 people.

The Chicago-based carrier has more service to Asia than any other U.S. airline. United earlier this week pulled its full-year guidance because of the outbreak and said demand to China collapsed entirely and fell by 75% in the rest of the airline’s Asia network. United also on Friday announced it would postpone its investor day, which was scheduled for next Thursday.

United is now offering some widebody pilots a month off in April at the pay rate for 50 hours a month, lower than the roughly 80 hours pilots normally work, wrote Todd Insler, a United captain and chairman of the United branch of the Air Line Pilots Association, in a note to union members.

“The reductions in block hours has resulted in lower line values and fewer flying opportunities in some fleets,” he said. “We are preparing for the possibility of further reductions to our schedules as the virus spreads.

United did not immediately respond to a request for comment.

The virus is threatening to end a boom in air travel that helped propel U.S. airlines to a decade of profitability. Airline stocks fell more sharply than the broader market as corporations pulled back on business travel raising concerns about a broader slowdown in demand.

United’s pilots, like those at American and Delta, are in the middle of contract negotiations with the company.

“As of now, there has been no impact on our negotiating strategy or timeline,” Insler told pilots in his note. “During negotiations both sides always keep economic cycles and external events in mind. Our goal remains ensuring we have a robust contract that protects our pilots throughout their careers in all economic cycles.”