Former Bebo CEO Joanna Shields and Shine Group Chairman and CEO Elisabeth Murdoch have formed a content start-up to produce across media platforms, both online and offline, with a focus on social engagement, according to sources.

The new venture, which does not have a name, is being financially backed both by Shine and by Shields, who left AOL this summer after running its community and communications division.

Shields engineered the sale of social networking site Bebo to the Time Warner (TWX) online unit for $850 million in early 2008.

Sources said this new company, based in London, will invest, develop and partner to create a variety of content offerings that also incorporate interactive and social networking elements. It will also help the vast array of Shine content in interactive efforts.

Shields will be CEO of the start-up, which will operate under Shine, an independent and private television production company with programming in 24 countries.

In the U.S., for example, its Reveille unit is responsible for such shows as “Ugly Betty” and “The Biggest Loser.” (Both of which are BoomTown faves.)

Shine’s fast growth has been spearheaded by Murdoch, who is the daughter of News Corp. (NWS) head Rupert Murdoch.

But Elisabeth Murdoch has struck out on her own in forming Shine, which already has shown a strong interactive bent for a television company.

The combination of television and Web content is an arena that many are once again jumping into, aiming at creating branded interactive content, fueled by advertising.

Former NBC Universal exec Ben Silverman–who sold Reveille to Murdoch, in fact–has recently left his programming job at the television network to start a similar kind of company with longtime entertainment and Internet kingpin Barry Diller of IAC/InteractiveCorp (IACI).

And former ABC programming and Yahoo exec Lloyd Braun also runs a television and Internet production company with longtime Hollywood player Gail Berman, including recently creating the Wonderwall celebrity news site for Microsoft (MSFT).

In addition, Yahoo (YHOO) and a spate of small content start-ups, as well as big media companies, are all trying to figure out how to create and monetize content online in a multimedia effort that bridges all kinds of distribution vehicles and more deeply involves viewers.

Bebo was actually trying to do that too. Under Shields, it had been a pioneer in creating a variety of innovative online original content, including “KateModern” and “Sofia’s Diary.”

But new management at AOL, now headed by former Google (GOOG) exec Tim Armstrong, has sidelined Bebo to its new ventures division and is likely to try to sell it. Company execs at both Time Warner and AOL now say the purchase was a costly mistake.

That might be true, but it was clearly a financial coup for Shields–who has worked at both Google and RealNetworks (RNWK)–and Bebo investors.

And, given the track record of both Shields and Murdoch, it will be interesting to see what they come up with.

As BoomTown argued yesterday in a piece on the landscape of Yahoo if Microsoft completes its purchase of the Internet portal, Yahoo (YHOO) certainly knows how to make online content.

As we wrote: “For all its history, right down to today, even with all these dumb widgets competing for users’ attention, Yahoo continues to natively understand how to to entertain, inform and serve up their own and others content to consumers.”

Case in point, an attractive new site it launched today called Shine, which is aimed at women from their mid-20s to their mid-50s.

As you can see from the image below, it is a very well-done site, incorporating a lot of the good stuff in the same genre from around the Web.

Does it look a bit like the sassy properties of Sugar Inc.? Is it light and frothy like Glam Media? Does it feel a bit like DailyCandy, in its focus on the shopping as a sport? And, is it as helpful as iVillage (and does it even “borrow” a wiggly “i”)?

Yes indeedy to all!

Imitation is a form of flattery, I suppose, although Yahoo’s site feels fresher than any out there and it has an aspirational and hip feel that women will like, I think.

I’d call it an Eat-Pray-Love mood, with a lot of Oprah mixed in.

More importantly, it is clearly a good market for Yahoo’s advertisers, who all aim to reach this high-spending but underserved demographic online.

Yahoo is trying to reinvigorate its lackluster efforts here, as well as making plans to further drill down into related topics like parenting, sex, food and wellness that are present on the Shine site now.

While it looks a lot like a blog plus, Shine obviously has social written all over it and a wide range of communications tools will be easy to layer over the service.

It also is smart in its partnering with lots of media companies like Hearst and in pointing across the Web to give users a more comprehensive offering.

But can Yahoo compete in a very crowded field with such a late entrant? Probably. It recently put up a celebrity site called OMG, which has grabbed significant traffic quickly.

And while we honestly could care less if men look bad in skinny jeans (um, yes!), there is probably something on the very-full page of interest to everyone.

The Shine site has Brandon Holley as its editor-in-chief, but the effort in the arena is being helmed by Amy Iorio, who is the VP/GM of Yahoo’s Lifestyles unit. It all rolls up under Yahoo Media SVP Scott Moore.

While Yahoo PR will probably blah-blah too much about “starting points,” which is the latest buzz word from top brass, related to Shine, it should just hush up and realize Yahoo’s many owned-and-operated media conglomerations just need decent support and promotion to stay as strong as they are and to keep them as one of the bright spots at the company.

Here’s a screen shot of the site (click on the image once to make it appear on another page and then again to make it larger):