SRL for [billing]: According to one person familiar with the airline , the buy - out group -- led by United 's pilots union and UAL Chairman Stephen Wolf -- has begun [billing] UAL for fees and expenses it owes to investment bankers , law firms and banks .
ARG-0: the buy - out group -- led by United 's pilots union and UAL Chairman Stephen Wolf -- | ARG-2: UAL | ARG-3: for fees and expenses it owes to investment bankers , law firms and banks