French TV and radio stations can tweet as much as they like but must stop telling people to consult them on Twitter and Facebook, which amounts to advertising for those sites, France's media regulator says.

Media usage of mini-messaging via social networking sites has mushroomed with France's frenzied coverage of the arrest of former IMF chief Dominique Strauss-Kahn in New York on attempted rape charges, but the CSA media industry regulator is warning that such covert advertising is against the law.

In a world where global communication has taken yet another leap via social networks, the media regulator's response fueled a debate that quickly painted France as stuck in a time-warp.

You cannot say 'look us up on Facebook' or 'Look us up on Twitter'. What we advise people to say is: 'Look us up on the social networks' -- because Facebook and Twitter are commercial brands, CSA spokeswoman Christine Kelly told Reuters.

Kelly, a former journalist, explained in several radio interviews this week that covert advertising, visible or audible references to branded products outside of dedicated advertising periods, has been banned in France since 1992.

She said radio and TV stations which refer their audiences to Twitter and Facebook by name are breaching that law and risk fines if they fail to comply. They should stick to telling people to check their social networking pages, without referring by name to the two giants in that domain, she said.

The CSA's warning comes as one of France's most widely consulted dictionaries released a new edition that includes the word 'tweet' for the first time in a country that has long been a reluctant importer of English words.

That makes no difference as far as we're concerned. The word Coca Cola's is there too, said Kelly.

She nonetheless said it was not immediately sure if the word tweet, a verb and noun that has emerged as a result of the brand name explosion of Twitter, would also fall foul of France's rules on mentioning brand names on air.

In the days after the May 14 arrest of Strauss-Kahn, formerly the IMF managing director and the man seen as frontrunner to win France's 2012 presidential election, the CSA also struck out.

It took French TV stations to task for broadcasting images of him being escorted handcuffed to a New York courthouse. While legal and commonplace in the United States, such images cannot be broadcast in France ahead of a guilty verdict, due to laws protecting the presumption of innocence.

The latest news of the brand name bans triggered responses of surprise and indignation on the web, and debate in mainstream foreign media about whether France's rules had passed their sell-by date in a world where the internet makes a nonsense of geographical frontiers.

As a New York Times webpage put it: Here's something you won't hear on French television news today -- For more information on the U.S. trial of Dominique Strauss-Kahn, follow us on Twitter.

Pierre Haski, a French journalist responded on the same web debate page that this narrow legalistic approach gives France an Asterix village outlook, as in the popular cartoon when the whole of Gaul was under Roman occupation except for a tiny Breton village still resisting the globalization of the time.

(Editing by Jon Hemming)