"The wholesale opportunity is ripe for the picking," Fries told the Morgan Stanley European Technology, Media and Telecoms conference on Thursday.
"If there's anybody on this call that thinks that BT Openreach isn't going to have competition for wholesale: there's just zero probability of that."
He said emerging fibre broadband network builders in Britain would be hit by the roll-out plans of Virgin Media-O2 - jointly owned by Liberty Global and Telefonica - and BT.
"I think the window is slowly closing for many of these alt-nets," he said. "There's not enough wholesale customers to support their network construction. And they only have a fraction of the funding they actually need."
(Reporting by Paul Sandle; editing by Guy Faulconbridge)