The Fox broadcast network plans to debut three new dramas and two comedies in the fall, keeping most returning series in their current positions to promote stability in its schedule and maintain audience loyalty.

The new shows are designed to hold onto the younger viewers who favor the News Corp. network while also appealing to a broader audience, Fox President of Entertainment Peter Liguori said at an upfront presentation to advertisers Thursday in New York.

Fox, propelled by the popularity of the “American Idol” talent show and programs including “24,” is poised to edge out ABC to become the No. 1 network for the May sweeps and for the season among the 18 to 49 viewers sought by advertisers. The network’s scheduling is complicated each fall by its broadcasts of Major League Baseball playoffs, which test viewers’ devotion to series interrupted by the sports coverage.

Fox plans to repeat its strategy of launching the new season several weeks before baseball broadcasts start. Last year that move paid off, with shows including “Prison Break” and “Bones” performing well.

The new and returning series will premiere in mid- to late August to fit in five to seven episodes before the baseball playoffs, Mr. Liguori said. Fox hopes the first block of episodes will interest viewers enough that they’ll tune in after baseball ends in October.

Shows not returning for the 2006-07 season include the early drama cancellations “Kitchen Confidential,” “Head Cases,” “Killer Instinct” and “Reunion,” plus comedies “Arrested Development,” “Stacked” and “Free Ride.” Comedy veterans “That ’70s Show,” “Malcolm in the Middle” and “The Bernie Mac Show” have completed their runs as well.

Fox’s schedule starting fall 2006:

Monday: “Prison Break,” “Vanished”

Tuesday: “Standoff,” “House”

Wednesday: “Bones,” “Justice”

Thursday: “‘Til Death,” “Happy Hour,” “The O.C.”

Friday: “Nanny 911,” “Trading Spouses: Meet Your New Mommy”

Saturday: “Cops,” “America’s Most Wanted: America Strikes Back”

Sunday: Comedy encores, “The Simpsons,” “American Dad,” “Family Guy,” “The War at Home”

Fox also announced its January 2007 schedule, which keeps “Idol” in its traditional Tuesday-Wednesday lineup and returns “24” to Mondays. Animated comedy “King of the Hill” also returns in January to Sundays at 7:30 p.m.

Fox’s schedule starting January 2007:

Monday: “Standoff,” “24”

Tuesday: “American Idol,” “House”

Wednesday: “Justice,” “American Idol” results show, “The Loop”

Thursday: “‘Til Death,” “Happy Hour,” “The O.C.”

Friday: “Bones,” “The Wedding Album”

Saturday: “Cops,” “America’s Most Wanted: America Strikes Back”

Sunday: Comedy encores, “King of the Hill,” “The Simpsons,” “American Dad,” “Family Guy,” “The War at Home”

Fox and CBS, the most-watched network, have both touted the stability of their schedules in presentations to advertisers.

Among Fox’s returning shows is teen drama “The O.C.,” which will premiere after baseball ends.

“We’ll have more original episodes in more contiguous blocks,” Mr. Liguori said of “The O.C.”

The new drama “Vanished” will run with “limited interruptions” in fourth quarter 2006, he said.

Despite changes in the schedule driven by the midseason series “24” and “American Idol,” Fox is keeping its core dramas in the same time periods for fall.

“Prison Break” will remain on Mondays at 8 p.m. (ET), “House” stays at 9 p.m. on Tuesdays and “Bones” sticks with its 8 p.m. Wednesday slot.

The 20th Century Fox FBI pilot formerly known as “Primary” has been renamed “Standoff,” while the Warner Bros./Jerry Bruckheimer legal drama “American Crime” is changing its name to “Justice.”

This fall also will mark the debut of Fox’s new Saturday late-night talk show, “Talk Show With Spike Feresten,” which premieres Sept. 16 at midnight, after “MadTV.”

Other Fox projects include “Duets,” a music reality competition from “American Idol” host Simon Cowell in which established singers are paired with unknowns. “Duets” will air for four weeks on Thursdays and Fridays before the Major League Baseball playoffs start.

The 20th Century Fox comedy “The Winner,” which profiled a successful man’s look back to when he was in his twenties, will be scheduled in midseason.

The Mark Burnett/Amblin/DreamWorks reality series “On the Lot,” which gives 16 hopefuls the chance to become a Hollywood director, will premiere in late spring to give it exposure during Fox’s season finales.

For the past few years, Fox has had two distinct schedules: fall and midseason. The network usually finishes in third or fourth place among broadcasters in the fall in the sought-after adults 18 to 49 demographic, thanks in part to program disruptions caused by postseason baseball and what has often been lackluster series premieres.

In January Fox has been making up for lost ground, driven by the returning “American Idol” and “24.”

Fox was the fifth English-language network to announce its fall 2006 schedule to advertisers this week in New York. The CW announced its schedule Thursday morning.