International watchdogs are urging British mobile phone customers who are stung by exorbitant charges for downloading data abroad to report incidents where they feel they have been the victim of "abusive" tariffs.

The call follows an investigation by The Times that revealed that some customers have been charged nearly 100 times more for downloading data, such as e-mails or music, over their handsets while abroad, compared with rates in the UK.

Regulators have so far been reluctant to act because they say the present market for data downloads is too small. However, a host of companies are banking on mobile internet services becoming hugely popular. In the past week both Yahoo and Google have announced services that make use of wireless networks to deliver content to handsets.

They are not alone in wanting to put themselves in their customers' hands. Last week Microsoft said that its new web-based services, which include online versions of its most popular software packages, would be available from mobiles supporting its Windows software. Television producers already make special "mobisodes" of some programmes, designed for mobile phones and downloadable over the net. 

To vote in Times Online's e-poll on download charges click here.

Mobile phone companies have defended the huge cost of downloading data overseas despite conceding that prices "need to change". The European Commission has already told Vodafone, Orange, T-Mobile and O2 that the high costs of data services had "not escaped its attention".

One Orange customer described to The Times how he returned home from a business trip abroad to face a bill of more than £650 after downloading just over 80 megabytes of data. His contract said that in the UK he paid only £45 a month for 400 megabytes.

A spokesman for Orange told Times Online: "This is a market thing. From a UK perspective it is fair within the market. Our prices are as fair as they possibly can be."

Orange and other networks say the high prices are due to their relationships with their partners in other countries. When a mobile phone user downloads data abroad it travels via two networks – the company with which the user is registered and a partner in the overseas country.

However, Orange added that it is "reviewing our pricing to ensure that consumer customers who download data while abroad are receiving the best value".

T-Mobile, which advertises the cost of data downloads abroad on its website at £7.50 per megabyte, said: "T-Mobile UK’s long-term aim is to permanently reduce the wholesale costs of roaming abroad charged by foreign operators, with the ultimate aim of continually offering improved rates to our customers."

In the spring of 2000, telecoms companies paid £22.5 billion in 3G – or internet phone – license fees in the UK alone, hoping to cash in on the new market.

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