BTopenworld is the most complained about internet service provider in the UK, according to telecoms watchdog Oftel.

The ISP receives 1.6 complaints per 1,000 customers compared to an industry average of 0.4.

AOL was the best performing with less than 0.1 complaints per 1,000 customers.

Ntl also received few complaints for its internet service but was the most complained about fixed line provider with 0.8 complaints per thousand customers.

Taking it seriously

The main complaint for internet users overall was difficulty getting hold of a company and being left on hold for up to 40 minutes.

Net's worse performers

BTopenworld: 1.6 complaints per 1,000 customers Pipex: 0.6 One.Tel: 0.3 Tiscali: 0.2

Second in the list of frustrations were companies ignoring complaints and failing to respond to customers.

And the third most popular bugbear was contracts that limited the number of hours users could access the internet each month.

BTopenworld is determined to improve its service.

"Clearly we are not happy to have that sort of record. We treat any customer complaint very seriously," said a company spokesman.

Many of the calls were made during the time broadband interest skyrocketed due to a drop in the price and the ISP had "struggled to cope", he admitted.

The company has listened to complaints about restrictions on its dial-up net service and has changed the rules about how long people can stay online.

Merged customer service

BTopenworld has struggled to make a profit on its internet businesses.

The fact that we are publishing the details of complaints should be an incentive to resolve problems Oftel spokeswoman

The dial-up service has just gone into the black and broadband is expected to follow suit next year.

It has also been overshadowed by a rival direct access product introduced by BT Retail.

Persistent rumours that the troubled firm would eventually be merged into BT Retail were born out this week as BT announced many of the functions of the ISP would now be handled by the parent group.

This includes customer service, which could mean there are more call centres available to answer complaints.

Oftel receives around 100,000 complaints each year about fixed and mobile telephone and internet services in the UK.

No teeth?

It is the first time the watchdog has published details of internet complaints, which it says are on the rise this year.

Between April and September Oftel received nearly 7,000 complaints about ISPs.

It admits that it does not have direct powers to deal with bad customer service but does talk to offending firms on a regular basis to sort out issues customers have.

"The fact that we are publishing the details of complaints should be an incentive to resolve problems," said an Oftel spokeswoman.