For fixed broadband services, TalkTalk Group (including the old Tiscali UK business) generated the most complaints as a proportion of its customer base, at 0.61 complaints per 1,000 subscribers.
Ofcom said that its data, which covers the fourth-quarter period from October to December 2011, shows that most of the complaints were about "line faults and other service issues".
TalkTalk was also the most complained-about provider of landline phone services, with 0.78 complaints per 1,000 customers, largely "driven by issues relating to billing and customer service".
The least complained-about fixed broadband providers over the three-month period were Sky and Virgin, with 0.17 and 0.18 complaints per 1,000 customers respectively.
Virgin Media was also the least complained-about landline provider, at 0.18 complaints per 1,000 customers. The cable operator has attracted the least landline complaints for the last five quarters.
Ofcom said that overall mobile complaint levels were "much lower" than for landline and fixed broadband services. Orange was the most unpopular provider, generating 0.17 complaints per 1,000 customers.
The regulator found that the "significant increase" in complaints against Orange was driven by its announcement of an increase in monthly prices for all customers, including those who were tied into existing contracts.
Three was the second most complained-about mobile provider, at 0.15 complaints per 1,000 customers, and most of these were about "disputed charges and customer services".
An Ofcom spokeswoman said: "The quarterly report aims to provide useful information for consumers, and also to incentivise telecoms providers to improve their performance."
Despite being once more ranked among the most complained-about providers, TalkTalk said that the figures show a reduction in complaints on last year, when the firm was fined millions of pounds by Ofcom for billing customers for services they had not actually received.
"We are pleased that Ofcom saw less than half as many complaints about our broadband service than this time last year," said a TalkTalk spokesman.
"While there will always be variations in the quarterly data we are confident that the long-term trend is positive - fewer complaints, more calls being resolved first time, and improving customer service.
"There is more work to do, but we are confident that the measures we've put in place are paying dividends."
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