CBS's announcement earlier this summer that Julie Chen, the news reader on ''The Early Show,'' would be a host on ''Big Brother,'' one of the network's two summer reality programs, sent ripples of anger through the network's news division.

There was grumbling that it was inappropriate for a news personality like Ms. Chen to participate in ''Big Brother,'' a prime-time game show that is managed by CBS Entertainment. Her appointment to the program kicked off a renewed debate over whether the lines between network news and entertainment were becoming too blurred. Andy Rooney, the ''60 Minutes'' commentator, publicly called her role in the program ''a further deterioration of news standards.''

Now, executives close to the program say, Ms. Chen is doing what she can to maintain her stature as a newscaster, heatedly fighting with ''Big Brother'' scriptwriters, who have been handing her lines that are hardly the stuff of network news people.

For instance, after the first episode of ''Big Brother,'' Ms. Chen was heavily criticized by TV critics for uttering the following decidedly un-newsy statement, ''Wow. That was intense.'' Earlier, Ms. Chen had told the audience, ''Wow, that's wild.''