The move follows an investigation by the watchdog into reducing harm caused by abandoned and silent calls.

Organisations are allowed to make a limited number of abandoned calls.

However, Ofcom found that during one of its telemarketing campaigns, TalkTalk exceeded this limit by a substantial amount on four separate occasions between 1 February and 21 March 2011.

The phone company also failed to ensure information messages were played, meaning consumers received silent calls.

In total, TalkTalk made approximately 9,000 silent and abandoned calls to consumers.

Abandoned calls occur when a call is made and a person answers the phone, but the caller hangs up. Ofcom’s policy is that abandoned calls must include a recorded information message that says who has called them and how they can opt out of future sales calls.

A silent call is where the phone rings but there is only silence when the person answers it and no information message is played.

Abandoned and silent calls can be caused by a number of things, including the conduct of agents handling calls, or the use of call centre technologies such as answer machine detection (AMD) technology.

Claudio Pollack, Ofcom’s consumer group director, said: “Silent and abandoned calls can cause annoyance and distress to consumers. Companies must abide by the law and Ofcom’s policies. If they fail to do so then Ofcom will take firm action.

“Today’s penalty sends out a strong message to organisations using call centres that they must comply or face the consequences.”

Responding to the fine, Richard Lloyd, executive director at consumer group Which? said:

“It’s good to see Ofcom flexing its muscles against abandoned and silent calls. With so many people telling us they are being bombarded by nuisance calls and texts, we have been calling for all the relevant regulators to work together to properly police and punish those responsible with substantial fines and suspension of licences.”

A TalkTalk spokesperson said: “In February and March 2011, two of TalkTalk’s suppliers, Teleperformance and McAlpine Marketing, made a number of silent and abandoned marketing calls.

“TalkTalk demands high standards from the companies it works with and as a result TalkTalk immediately stopped using these suppliers. Both suppliers addressed the root cause of the problem and TalkTalk will fully recover the financial penalty imposed by Ofcom from these companies.

“TalkTalk works with all its partners to ensure that regulations are adhered to and that customers continue to get good service and best value.”