Cogent Communications Group Inc. CEO Dave Schaeffer made the comments at a congressional hearing about Comcast's proposed $45 billion takeover of Time Warner Cable Inc. on Thursday.
Schaeffer said that after Cogent began delivering Netflix's traffic in mid-2012, its relationship with Comcast worsened and Comcast began to stop increasing the capacity of its hardware to accommodate the increase in traffic.
He said Netflix was forced to cut a direct deal with Comcast to improve streaming to customers, which began to be plagued by buffering, delays and pixelated pictures.
"That's an abuse of market power," Schaeffer told the House antitrust subcommittee. "A larger and more combined company would have even more market power."
Comcast executive vice president David Cohen said Comcast was forced to react when the flow of traffic with Cogent went from roughly equally to Cogent sending five times as much data as Comcast was sending back.
"That triggered the need for a discussion and a negotiation about the need to come to a form of paid peering relationship," Cohen said. Such paid deals are common when the balance of traffic is out of whack, he said.
Netflix declined to comment.
Netflix Inc. has come out against the merger, saying in its letter to shareholders last month that a combined company would "possess even more anti-competitive leverage to charge arbitrary interconnection tolls" on services like Netflix.