"There is a recognition that we have to change," Regan told British media.
"We are in danger at the moment of keeping perpetuating the Champions League brand as the answer to everything.
"I think people will get bored with Champions League predictability, particularly in markets where your own country isn't represented for long spells in the season.
"How do we keep the dream alive in Europe? For me that is cross-border... If you look at the TV audiences at the moment in the markets where teams are out, the Champions League audiences are in decline."
Regan, who is part of a UEFA group investigating how cross-border competition would be a feasible strategy, said one potential option would bring groups of six countries together to play in tandem with respective domestic leagues.
"If we do nothing, the big countries will get bigger and bigger while the small countries will never be able to compete in Europe," he added.
(Reporting by Shravanth Vijayakumar in Bengaluru)
