BT has been ordered to improve its wholesale services after a barrage of complaints from customers of companies that rent capacity from the telco giant.

Oftel last week issued a Provisional Order - a serious disciplinary move - after customers reported problems such as being left without a phone for up to 33 days, and losing essential services without warning.

BT's Calls & Access service allows competing providers to offer their own telephone services direct to customers, over the BT network. The service hit the headlines in April when service provider LocalTel used it to launch Screaming.net, an ISP with free call time.

LocaTel came under heavy criticism from customers who faced long delays when transferring from BT to its service.

"We're expecting BT to come up with a proper resolution for the problems," an Oftel spokeswoman said. "We're wielding a fairly big stick because we feel it has failed to come up with a reasonable solution."

BT said it had taken on more staff to deal with the process of transferring customers to the alternative service providers. "It has taken longer to process orders than LocalTel would have liked," a spokesperson added.

Jeremy Stokes, managing director of LocalTel, said, "People were starting to wrongfully accuse us of blaming BT for our own inadequacies."