Stoke's share was 1.75 million pounds -- the eighth highest among the 20 Premier League teams -- and Coates fears he faces a losing battle to regulate the fees agents receive.
"I find it a kind of frustrating period because of the difficulties you have in getting the players you'd like to have. It's a highly competitive market and agents play the field," Coates told British media.
"They are looking to maximise their income and their player's income. They duck and dive, tell you one thing and tell somebody else another thing.
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"I'd like to have an agreement among all clubs about how much agents got paid, so a percentage or whatever, but we can't reach an agreement. It's a big chunk of money they get and that's going out of the game, but there's no change in sight."
(Reporting by Shravanth Vijayakumar in Bengaluru, editing by Ed Osmond)
