"We have been criticised for coming late to market but we did not want to rush it," said an O2 spokesman. "Earlier this year we were not happy with the service so we have waited."
The mobile operator claimed that its service has been designed to address current consumer unhappiness with broadband in the UK.
O2 plans to beat current broadband suppliers at their own game by making the service easy to set up, offering free 24-hour support based in the UK and only selling users a broadband speed which they can actually achieve.
"If we think they can only get 8Mbps, we will not even offer them the other two packages," said the O2 spokesman.
"A month in we will recheck and if people need to downgrade we will suggest that they do."
Be Broadband's kit is installed in unbundled exchanges and covers 50 per cent of the UK.
"That coverage will be expanded as the demand grows," the O2 spokesman said. "We have access to BT's IP stream if we need it and we have that option if we don't have coverage in a specific area."
O2 mobile subscribers will pay £7.50 per month for up to 8Mbps, £10 for up to 16Mbps and £15 for up to 20Mbps.
Users will be offered 100 free texts a month that can be sent from their PC, address book synchronisation between PC and mobile phone, and emails delivered to their mobile phones.
However, those who are not existing O2 customers will pay £10 more for their broadband connection and will not be offered the additional services.
The £7.50 minimum cost is more than the average broadband bill for UK households, which is £5.50 per month. This compares to £2.54 in Finland for an average speed of 21.7Mbps.
O2 has also announced that it will allow its mobile phone users free access to MySpace in November and December.
The partnership with the social networking site will enable O2 customers to view, track and contribute to their MySpace pages on the move.
O2 said that an internal survey of its customers found that the number one piece of content they craved outside search was access to their social networking pages.
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