Chinese viewers on Tuesday welcomed a ban on commercials during popular television dramas, but advertising professionals warned it could result in billions of yuan in losses for broadcasters.

The State Administration of Radio, Film and Television (SARFT) announced Monday that from 2012, adverts would be prohibited during television dramas "to ensure... the continuity of the audience's viewing experience".

It was the latest in a series of directives issued over the past few months as the media watchdog looks to exert more control over television and woo back viewers lost to the Internet.

The growth of China's online population -- now the world's largest at more than 500 million -- has posed a huge challenge to attempts by the country's Communist rulers to control the media people consume.

The 21st Century Business Herald newspaper reported recently that one of the the main priorities for SARFT's new director Cai Fuchao after he took office in June was to increase television viewing.

"I strongly support this, because some advertising is sometimes longer than the drama itself," one viewer posted on Sina's popular Twitter-like weibo site, echoing general online sentiment.

Bi Yantao, head of the advertising department at southern China's Hainan University, said SARFT had implemented the measures because the number of advertisements shown during television dramas had become "intolerable".

"There's a joke that says that when you watch ads, all of a sudden a TV drama pops up," he told AFP.

According to an August state media report, more than 26 percent of China's Internet users no longer watch television, and 43 percent are not watching as much, as they turn to the web for entertainment.

In Beijing, meanwhile, only 38 households in 100 now have their television on every evening, against 75 just three years ago, the state-run Beijing Youth Daily said.

Nonetheless, television dramas -- usually uncontroversial love stories or historical sagas as broadcasters seek to abide by strict censorship rules -- remain hugely popular in China.

Bi said the ruling would have a large impact on broadcasters' advertising revenues, particularly after SARFT this year also placed stringent limits on popular entertainment shows.

"Friends who work in television advertising have told me that China's television stations will incur at least 20 billion yuan ($3.1 billion) in annual advertising losses," he said.

Liang Deming, who works in media research at advertising agency Charm Communications, said 40 to 50 percent of broadcasters' overall advertising revenue came from television dramas.

But only 10 to 20 percent of this comes from commercials inserted into episodes -- those that have now been banned -- rather than ads placed directly before or after.

But both Bi and Liang said broadcasters and advertisers would find a way round recent limitations.

"They could reduce each episode to 30 or even 20 minutes so as to legally insert ads in-between, include ads in the credits, or even put logos in the corners of the screen," Bi said.

"There's already a lot of product placement, and this is also a good advertising method," he added.