Chris Clark, BT wireless broadband chief executive, said that BT was keen to give its Wi-Fi customers access to more hot spots, and suggested that a deal with T-Mobile was imminent.
"There are only three large-scale operators in the UK: BT, The Cloud -- who we already have a deal with -- and T-Mobile," said Clark. "The other operators are important, but they are niche."
"Our focus is to get the scale operators working together," Clark said, in an interview in which he also talked about BT's Wi-Fi price cuts.
BT's roaming agreement with The Cloud, the UK's largest Wi-Fi network, gives it access to some 4,000 hot spots. At the last count, T-Mobile had 500 hot spots in locations such as Starbucks coffee shops and Texaco petrol stations.
T-Mobile did not immediately respond to a request for comment.
Without roaming deals, a customer on one UK Wi-Fi network has to pay again if they want to use the hot spots of another. Given the high prices levied by some operators, this has been a barrier to wireless take-up.
According to one analyst, it's important that this problem is overcome.
"Simple roaming between Wi-Fi networks is essential. It needs to be like banks' ATM cash machines: ideally, they all interconnect. At a push, two large and well-branded networks can coexist. But fragmentation reduces the overall value and utility of the technology," said Dean Bubley of Disruptive Analysis.
At present, Openzone customers can use The Cloud's hot spots without incurring any additional fee. Bubley thinks it's important that this remains the case.
"Users might pay extra to roam at a hot spot at Heathrow if they really have to, in the same way they might pay a £1 fee to get cash out of an ATM in a nightclub at 2 a.m. when they're drunk. But in 95 percent of cases, there should be no incremental charge or inconvenience."