* Discovery Channel plans four new series for 2011-12
* Shows include "Life on Wire" and "Swamp Brothers"
* OWN network brings out six new series
NEW YORK, April 14 (Reuters) - Discovery Channel, home to a string of popular adventure and nature shows, will roll out a TV schedule next year featuring a circus family, woolly mammoths and reptile rescuers, among other oddities.
Discovery Channel, which struggled at times last season to retain viewers, has scheduled three new specials and four new series for the 2011-12 season, joining returning programs including "Storm Chasers" and "Deadliest Catch."
Discovery will introduce its full lineup to advertisers during a presentation later on Thursday, before it begins the process of negotiating commercial rates for the upcoming season during the so-called upfront period.
TV advertising has surged in recent months on demand from the automotive, retail and telecommunications categories, providing a boost in sales for cable network owners such as Discovery Communications (DISCA.O) and Time Warner Inc. (TWX.N)
The result, analysts say, is that commercial rates could be up by 10 percent or more in this year's upfront market, when cable and broadcast networks sell the bulk of their time for the next TV season. Broadcast networks NBC (CMCSA.O), CBS (CBS.N), Fox (NWSA.O) and ABC (DIS.N) will introduce their lineups in May.
Discovery Communications, in addition to the Discovery Channel, owns TLC, Animal Planet, Investigation Discovery, Science and Discovery Fit & Health.
It is also the owner, along with Oprah Winfrey, of the new OWN network, a largely female-oriented mixture of lifestyle, advice and uplifting shows. The network has suffered some audience ratings setbacks since its highly publicized launch in January.
OWN plans to introduce six new series in the upcoming season and will return "Our America With Lisa Ling," "Ask Oprah's All Stars," "Enough Already!" "In the Bedroom with Dr. Laura Berman" and "Oprah Presents Master Class."
OWN's new series include "Confronting," "I Owe You My Life," "Louie Spence Dance Project," "My Mom and Me," "Sweetie Pies," and "Unfaithful: Stories of Betrayal."
The titles alone give some indication of the different audiences served by OWN and Discovery, which next year will feature specials titled "Frozen Planet," "Where's My Mammoth" and the wildly popular "Shark Week."
As for new series, Discovery will stick with its traditional lineup of nonfiction programs that often showcase odd jobs and bizarre settings. "Penn & Teller's Secrets of the Universe," for instance, will feature 10 hard-to-believe stories, only one of which is a fake.
In "Life on a Wire," the audience will follow the Flying Wallendas, a circus family, while in "Swamp Brothers," Robbie and Stephen Keszey will be featured at work in their reptile sanctuary.
The final new show for the 2011-12 season is "Best in the Business," which Discovery is billing as "the ultimate battle of job-skill supremacy that celebrates the creme de la creme of the American workforce." (Reporting by Paul Thomasch, editing by Matthew Lewis)