Telco giant BT has announced the launch of a new mobile phone service, Mobile Sense, less than a year after selling off its mobile arm, BT Cellnet.

BT claims the move back into the mobile market has been made in response to requests from its customers, who complained current mobile costs were too complicated and inflexible.

The service, run through BT's website, will allow customers to select the right package based on how many minutes and text messages they wish to use per month. Customers will be able to access their account to view their credit and generally keep tabs on their mobile expenditure.

"With this product we have a unique proposition that gives online customers complete control over what they are charged, even allowing them to change their pricing packages every month if necessary," said Pierre Danon, chief executive of BT Retail.

Users will be able to select from one of 12 handsets displayed on its website, including Sony and Nokia models.

BT will be buying airtime from former mobile subsidiary O2, which saves the company from setting up new networks and works out pretty well for its old ally. The company estimates revenues of £44m by 2005.

The deal is similar to BT's corporate model launched back in April, using airtime purchased from O2 to create tailor-made packages.