BEIJING - Couch potatoes will be able to enjoy TV dramas without interruption once a new regulation comes into effect next year.

A supplementary provision to the regulations that govern radio and TV broadcasting prohibits commercials from breaking up TV dramas, which last 45 minutes on average. The ban was released on Monday by the State Administration of Radio, Film and Television and goes into effect on Jan 1.

The provision was issued "in accordance with the people's interests and demands", Xinhua quoted an unidentified official at the administration as saying on Monday.

The top broadcasting watchdog is now requiring all TV broadcasters to re-arrange their programs and delete commercials that are scheduled to air in the middle of soap operas and other dramas.

Shi Lan, spokeswoman of Dragon TV in Shanghai, one of the most profitable TV channels in the country, said she and her colleagues are still discussing what changes they can make to keep the loss caused by the ban to a minimum.

"It's unrealistic to say that the restriction won't cost us anything," said Shi. "But still, we plan to strictly follow the rules."

Other TV channels, among them the International Channel Shanghai, which is broadcast in English, and the New Entertainment channel, said they show few TV dramas and therefore expect to see little to no effect from the restrictions.

Chen Gang, a professor of advertising at Peking University's school of journalism and communication, praised the ban.

"Placing a limit on commercials appearing during TV dramas not only gives viewers a better experience but also leads to fiercer competition among TV stations," he said.

"The number of TV stations in China is huge, and the competition among them is vicious. The weaker the station is, the more it relies on TV dramas and commercials. Under the regulation, such TV stations will have to develop their own programs instead of simply broadcasting TV dramas."

Others think the regulation will mean hassles.

"I heard about the new ban on Wednesday and was caught off guard," said a planning manager at a foreign advertising company in Beijing, who declined to give her name. "My company had signed contracts with Jiangsu TV on airing commercials during next year's TV series. Now we have to renegotiate the whole plan.

"Commercials bring most profits when aired during TV series, followed by those aired at the beginning or the end of an episode."

She said it will not be wise to allow commercials to appear only at the beginning or end of TV episodes. That, she explained, forces stations to run long strings of commercials, which repel viewers.

Gong Libo, director of Jiangsu TV's marketing center, had similar thoughts.

"The 6.5-minute blocks of commercials that are now aired during TV dramas will be canceled, instead of being moved to the beginning or the end of a TV episode", Gong said on his micro blog on Nov 24.

The current regulation imposes a maximum length of 18 minutes on blocks of TV commercials that are broadcast from 7 pm to 9 pm.

Dramas broadcast during those hours can contain no more than one block of commercials and that must run for less than 60 seconds.

At other times, the same regulation, allows two blocks of commercials - each lasting 90 seconds at the most - to appear during TV dramas.

A previous version of the regulation, which was in effect from 2004 to 2010, did not allow commercials to run during TV dramas broadcast from 7 pm to 9 pm. Shows appearing outside of those times could contain one block of commercials lasting less than 2.5 minutes.

Xu Junqian and Wang Qingyun contributed to this story.