The staff gathered at AoT's main office on Vibhavadi Rangsit Road to demand an explanation from president Makin Petplai.
Mr Makin told them that AoT is currently holding excess liquidity totalling 37 billion baht and is undecided on where to invest the money.
He did not rule out a possible purchase of bonds issued by the Finance Ministry as part of the caretaker government's attempts to pay farmers, but insisted that he was under no political pressure to make a purchase.
Bond purchasing will not be on the agenda at a board meeting chaired by Sqn Ldr Sita Divari on Thursday, he added.
The caretaker government is looking for cash to make overdue payments for farmers involved in its rice subsidy scheme. It is seeking 130 billion baht to pay more than one million rice growers.
One way in which the government could generate the cash is by issuing bonds for state-owned firms to buy. AoT is believed to be one of its targets.
The AoT chief pledged that any investment made by the agency will not affect its development plans, including the expansion of Suvarnabhumi and Phuket airports and facility improvements at Don Mueang.