LOS ANGELES - The oldest remaining US daytime soap opera will air its final episode in September after 54 years and over 13,000 episodes, CBS television announced.

'As the World Turns,' originally started in 1956 by a Procter & Gamble media unit, has launched the careers of stars like Meg Ryan, Oscar winner Marisa Tomei and Oscar nominee Julianne Moore.

CBS pulled the plug on 'World' just three months after the network ended another popular drama, 'Guiding Light,' which aired its final episode after a 72-year run on radio and then television.

Both shows were run by TeleNext Media, a Procter & Gamble subsidiary set up in 1933 to promote the company's detergent products.

"It's extremely difficult to say good-bye to a long-running series that's been close to our hearts for so long," said Barbara Bloom, CBS senior vice president of daytime programming.

"The almanacs will show 'As the World Turns' as a pioneer of the format, a hallmark for quality with its numerous Emmy's," she said, referring to the US television awards.

The show also served as "the launching pad for many television and film stars and a daytime ratings powerhouse for parts of three decades," Bloom added.

The show's demise came amid declining revenues and a drop in viewership, a trend experienced by daytime television in general as more women go to work, shows become available online and the number of available cable outlets grows.

'World' garnered some of the best ratings in the 1960s, but they slipped steadily from 6.5 million viewers in 1993 to 2.5 million this year, according to US media accounts.

Set in the fictional Midwestern town of Oakdale, Illinois, what Bloom called "a treasured daytime institution" also presented the first gay male character on US daytime television in 1988.