Greater transparency has failed to reduce roaming charges

They gave their support at a conference in Paris where EU Telecom Commissioner Viviane Reding outlined her plans.

The proposed law will force mobile phone companies to cut their international roaming charges to the level of domestic cross-network calls.

Draft legislation is to be be published in April.

It will then be considered by the European Parliament and the Council of Ministers.

If the two bodies approve the regulations they could come into force in the second half of 2007.

Martin Selmayr, the official spokesman for Ms Reding, said: "We have a green light to go in the right direction."

He said that the regulators had given strong support to Ms Reding's plans and that they were going to work as a team to draft the new regulations.

Fantasy costs

The high cost of using a mobile phone abroad has long been a source of annoyance - and unexpected expense - to mobile phone users.

Consumers continue to pay unreasonably high prices for using their mobile phone abroad Viviane Reding EU Commissioner

It is thought that the roaming charges provide mobile phone companies with as much as 20% of their income.

But Ms Reding described the charges as "fantasy costs" because of the minimal extra real expense involved when one mobile phone company carries a call from a foreign visitor.

Since 2000 the charges levied by the various mobile operators have been probed several times by the European Commission.

It has become frustrated at the slow progress in bringing down charges for customers, even though the wholesale charges that operators pay to each other have fallen substantially.

As well as publishing its draft law in April, the Commission will also update its special website - launched last October - which lets people compare roaming charges throughout the 25 members of the European Union.

Ms Reding told the regulator's meeting in Paris that she was becoming increasingly frustrated.

"Prices appear to have remained essentially unchanged," she said.