Los Angeles - Sensible shoes or stilettos? Lifetime is still trying to figure out which fits best.

The women's cable network has struggled for years to change from plain Jane to glamour girl. But Lifetime's numerous makeovers have taken a toll: Its prime-time audience has plunged so much that the channel no longer even ranks among the top five favorite cable networks among women under 50, according to Nielsen.

Meanwhile, rival networks have been wooing women away with shows such as the "Real Housewives" series on Bravo, MTV's "Teen Mom," Showtime's "Nurse Jackie" and even reruns of "Sex and the City" on TBS.

The quandary for Lifetime has been a conflict between the viewers it seeks and those who tune in.

"There were a lot of people at Lifetime who wanted our viewer to be hipper and more fashionable," said Brent Poer, a former marketing executive at Lifetime who is now senior vice president at MediaVest USA, which buys commercials for Wal-Mart and Procter & Gamble. "That just wasn't who they were."

Lifetime's big gamble - snagging the fashion competition "Project Runway" from Bravo - didn't pan out. The show has proved a solid performer, but it has hardly delivered the ratings payoff to justify its $150-million price tag and the millions more spent on a legal battle against Bravo for the TV rights.

Now Lifetime is bracing for a shake-up in its corporate ranks. The network's chief executive - Andrea Wong, who engineered the "Project Runway" deal - is leaving. History Channel chief Nancy Dubuc is expected to replace her.

Lifetime executives say the network's shift away from shows that defined it in the past - serious dramas and women-in-jeopardy movies - is an attempt to broaden its reach without alienating its traditional audience.

Indeed, the current perception of Lifetime is, "'It's great for my mom, but I wouldn't watch it.' That has to change," said JoAnn Alfano, Lifetime's executive vice president of programming. "In some ways it's not rocket science. We want to invite all women into the tent and offer a cross-section of programming."

Although the network was never known for cutting-edge programming, Lifetime drew strong ratings for serious dramas such as "Any Day Now," about friends whose relationship was shaped by the civil rights movement, and "Strong Medicine," centered on a women's health clinic. Both are no longer on the air.

Some newer series, such as the one-hour comedy "Drop Dead Diva" and the drama "Army Wives," also delivered.

And it still gets a ratings pop from its staple movies: The ripped-from-the-headlines "Pregnancy Pact," about a group of high school girls who all decide to get pregnant, delivered 6 million viewers last month.

But elsewhere, Lifetime's picture is not so rosy. The network, despite repeated attempts, has failed to crack the highly profitable reality genre. It also swung and missed with comedy, most recently canceling "Rita Rocks" and still trying to decide whether "Sherri" will be back for a second season.

Advertising has declined along with ratings. According to industry consulting firm SNL Kagan, Lifetime's ad revenue fell 12 percent to $656.8 million in 2009, on par with other cable networks hurt by the weak economy. Kagan projects that advertising will bounce back 6.5 percent this year to $700 million.