The organisation has set out revised charges for operators to gain access to BT's network of phone lines which feed into individual homes, dubbed the local loop.
Companies such as Energis and Redstone will be able to offer broadband internet access to individual home-owners, competing against one another and BT.
They will pay £122 rental a year, with a one-off charge of £88 for each local loop connection, which is usually an individual house.
The operators will decide the final cost to be passed on to the customers.
Potentially reduced prices
BT has long been criticised by its rivals for delaying access to its local exchanges, although OFTEL said on Friday the process of so-called local loop unbundling was now "accelerating".
The benefits of competition include improved customer services and the driving down of prices.
The charges come into effect immediately, and BT has committed to opening 600 local exchanges to third parties within six months.
Broadband service providers allow home surfers to go online using a high-speed Asymmetric Digital Subscriber Lines (ADSL) connection that works via their telephone line.
ADSL lines are up to ten times faster than traditional modems and do not clog up the phone line.
More choice
Consumers will be able to keep BT for voice services, while using a competing operator for high-speed internet access.
BT must offer shared access from the beginning of 2001, with charges for this service to be established by Oftel early next year.
"This will offer not only operators, but consumers, a wider choice of options for providing and receiving voice and data services," said OFTEL director-general David Edmonds.
But earlier this month, five companies abandoned plans to offer broadband services, saying that the complexity of providing the service was too much for them.
Telewest, NTL, Global Crossing, Worldcom and KPNQwest are all scrapping their ADSL plans.