British Telecom could face legal action over its plans to re-brand its mobile phone arm O2.
Burford, the property group behind the Trocadero complex in London's West End, has a shopping centre called O2 in north west London.
The group was considering expanding the brand across Europe and is consulting its lawyers over BT's use of the name O2.
It said it is surprised the telecoms giant had not approached it before launching the new name.
BT announced yesterday that BT Cellnet, which it is spinning off as a separate company, would be branded mmO2, while the more familiar name for customers would be O2 - chosen for its connection with oxygen.
A Burford spokesman said: "We're taking legal advice about what our position is. It is clearly not passing off but it is a brand we have used to promote a particular type of product.
"One would have expected BT to have stumbled across the fact that something else was branded O2 and have been in touch with the company, but there has been no contact between us."
Burford owns 100 per cent of the brand name O2 and 25 per cent of the shopping and leisure centre on Finchley Road, which houses a cinema and the biggest Sainsbury store in the capital.
A BT spokesman said: "We do not believe there is an issue as the two companies operate in different fields. We have not received a formal approach, should we receive one we will respond to the company directly."
BT has not disclosed how much it paid to secure the rights to the O2 brand but it said it involved buying a website part owned by the talk-show host Ms Oprah Winfrey.
PA