PARIS Something doesn't add up in French President Nicolas Sarkozy's plans to remove advertising from Gallic pubcaster France Televisions -- and it's vexing locals far more than his plan to shutter the English-language feed on international news channel France 24.

Speaking at the Elysee Palace Jan. 8 in his first major press conference since winning the elections in May, Sarkozy set out his TV shakeup with immense style.

As time wears on, however, doubts are setting in about how the pubcaster will fund its five channels if it is forced to give up its advertising coin next year.

In 2006, France Televisions' budget hit $3.9 billion. Most of that came from the $170 license fee imposed on viewers, but some $1.2 billion was raised from advertising.

Sarkozy has ruled out a hike in the license fee and vowed the state will make up the difference by taxing private TV stations and new media -- mobile phone operators, telcos, Internet service providers, computer sales, etc.

But Culture Minister Christine Albanel's suggestion of a 1% tax would generate only about $439 million -- way below what France Televisions needs.

"The government went about this backward. The announcement was made to ban all advertising. Only afterward did they try to figure out how to finance it," says Matthieu Mouly, at French bank Natixis.

Albanel has hinted strongly that Sarkozy's January speech caught many in government by surprise. Removing ads "was a very strong political decision that could only be taken at the highest level and is a bit like a 'big bang,'" she says.

The government's already backtracked one step, allowing France Televisions sponsorship coin, worth around $115 million a year.

The nix on ads may not be a huge windfall for the pubcaster's commercial rivals TF1 and M6. On the day of Sarkozy's grand speech, shares at TF1 and M6 soared 10.66% and 4.79%. They're now back to pre-speech levels.

"It's not just Sarkozy making a gift to his friends controlling TF1, like some in France are suggesting," says an analyst, referring to Sarkozy buddy and TF1 owner Martin Bouygues.

French TV advertising is limited to six minutes an hour.

"Undoubtedly, if there's a restriction of TV ad time, prices will rise, benefiting TF1 and M6. But the key question's whether the advertising revenue increase will compensate for the new tax," says Francois Godard, at Enders Analysis.

TF1 and M6 aren't punching spectacular profits. They have little financial room for maneuver.

The weight of the new tax rests with Sarkozy. Having talked the talk with panache, he still has to walk the walk.