The airline notified pilots Monday that it would send furlough notices in September, Crain's Business Journal reported.

To achieve that many cuts, the airline will send out roughly 1,450 furlough notices, because many pilots are on military leave from the airline or have other commitments, Crain's reported.

The reduction is part of a 22 percent cutback in fleet size the airline is enacting to shed its least fuel-efficient planes, mostly Boeing 737s, Crain's reported.

United has already said it would trim 1,500 white-collar jobs and trim domestic flight capacity by 14 percent.

The pilot's union is negotiating with United to reduce the number of cuts, the report said.