The Costa coffee shop chain has joined the growing ranks of companies rolling out wireless local area network (Lan) hotspots for use by customers, putting the technology from BT into five of its shops in the City of London.

The move marks a further step in BT's plans to install 70 'Openzone' hotspots by the end of the year.

Costa joins Hilton Hotels, Welcome Break service stations and the Bluewater shopping centre in signing agreements with BT to host the wireless Lans. In August Starbucks signed a similar deal with T-Mobile.

Business subscriptions for the BT service start at £20 per month for 300 minutes, and unlimited use is set at £85 per month. It will also offer a pay-as-you-go service costing £6 per hour.

A spokesman for BT said that the service will be phased in gradually as shops receive pay-as-you-go cards.

European wireless internet service provider Megabeam also released details of prices for its business customers.

A monthly subscription will cost €86.25 (£55) per month for unlimited access. Two hours will cost €7.5 (£4.79).

The company also said that it had come to an agreement with hotel chain Queens Moat House to install and operate wireless hotspots at 25 hotels in the UK, Germany and The Netherlands.

Ryan Jarvis, chief executive at Megabeam, said that business travellers are "more likely to stay at a hotel with a high-speed wireless communications service rather than one in which they must deal with the inconvenience of cables and dial-up modems".

He added that tighter security is another important issue. "Once corporates know that wireless hotspots are secure they are happy to use the service," said Jarvis.

The BT spokesman assured customers that the Openzone hotspots are secure.

He explained that they use Nortel Networks' Contivity IP Services Platform to "bolt, padlock and board-up the back door by ensuring that all communication devices are encrypted to the highest level using triple-DES and encapsulated within a secure tunnel using IPSec".