Brussels  - The European Union is threatening to suspend a Slovakian law extending the monopoly granted to the country's postal service, suspecting that it might break EU competition rules, officials confirmed Wednesday.

The case concerns Slovakia's decision of February 15 to make a national monopoly of so-called "hybrid mail" services, in which the sender transmits a document to the post office electronically and the post office then prints and sends the document.

Such hybrid services had hitherto been open to competition. The Slovak move thus runs the risk of breaching EU rules, which state that the extension of a monopoly into a similar market where competition already exists is illegal.

Moreover, the Slovak postal service's hybrid mail system does not offer services, such as mail tracing, which commercial firms had previously offered, an EU statement said.

The EU's executive, the European Commission, has therefore sent a so-called "letter of formal notice" asking the Slovak government to explain its actions and warning that the commission could order the new rules to be suspended while the case goes on.

Such a letter is the first formal step in the EU's procedure for dealing with possible breaches of its rules. If the case is proven, Slovakia could have to revise the law or face court action.

"The commission has informed Slovakia that it might adopt interim measures to require the new provisions to be suspended so as to prevent serious and irreparable harm to competition," a statement from the EU executive said.

The Slovak government now has a fortnight to give its opinion on the EU's threat, and a month to reply to the commission's concerns more generally. (dpa)