symbian1Symbian, the company that makes operating systems for a large number of the world’s mobile phones, today will be announcing the launch of Horizon, its own path into the thick forest of app stores.

The company will make the announcement later this morning at MobileBeat2009, our application-focused conference today in San Francisco, where Symbian executives such as executive director Lee Williams will be speaking and elaborating on the product.

The service is not a full-fledged application store. It will see Symbian acting as a publisher, rather than an app store operator, and aims to lure the best developers to the Symbian platform with the promise of wide exposure across various apps markets and a range of free services and potential financial incentives. So far, Horizon has signed up Nokia, the world’s largest cellphone maker which has long relied on Symbian’s operating system, along with Nokia’s own application store Ovi. Horizon has also signed up Samsung and AT&T as distribution channels, and it plans to add further partners ahead of a full launch this October.

Horizon is a crucial move by Symbian to stay relevant to application developers, which is also necessary to keep handset makers interested in developing phones based on Symbian OS rather than the bevy of flashy new operating systems such as Android. Apple and Microsoft Windows also have competing operating systems.

Symbian says it will provide assistance in developing an mobile application, getting the application into different app stores that use the Symbian platform, marketing the app, and reconciling the billing across the the different stores—all without taking a cut, according to Shaun Puckrin, head of community support for Symbian and the man currently running the Horizon program.

Since last year, Symbian has been transitioning to an open-source platform. It is still the dominant smartphone OS world-wide, but it has fallen short in the novelty and buzz stakes, and sales, namely in North America. Worldwide, Symbian had 49.3 percent of the smartphone market in the first quarter, or 16.3 million units, Puckrin tells me, citing data from analyst firm Canalys. But in North America, Symbian accounted for only 3 percent of smartphone sales over the same time period. Symbian held 80 percent of smartphone sales in Asia-Pacific, 60 percent in EMEA, and 40 percent in Latin America.

There are some signs this is changing. In Nokia’s quarterly figures released today, the company reported a 6 percent increase in its U.S. sales over the same quarter last year, to 534 million euros. This is still a small number compared to the rest of its business world wide, but it makes North America the only market for Nokia that hasn’t seen a decline.

Another one of Symbian’s biggest weak spots right now is that, although it leads the smartphone market worldwide, Symbian-based handset owners may not be using their devices for expensive mobile data services nearly as much as others — namely iPhone users, if you believe AdMob’s statistics — do.

Of course, releasing another set of app store APIs doesn’t exactly set you apart today, given the massive proliferation of app stores in the market already. But there are few interesting details in what Symbian plans to do that might give it a glimmer of distinction.

According to our own source, Symbian is visualizing three tiers of engagement for developers: premium, professional and self-service. The lowest of these, self-service, is the set of widgets widely available already; the professional level includes Symbian signing the app (“signing” refers to a process of approving an application), uploading it to different stores and reconciling payment; the premium level covers all this plus the marketing of the app.

Puckrin, meanwhile, says Symbian will not go so far as to pay developers to work on the Symbian platform but it will run competitions with cash prizes, in addition to the other services, which Symbian anticipates will be free.

One of the unique features it hopes to offer is language translation: This is key since Symbian has particularly good market share in Europe, Asia and the developing world, but less so in the U.S., where many of the most interesting developers are today.

The emphasis on helping market apps could be another differentiator, as this is an area that is likely to become an even more important element for developers in an increasingly crowded market. Puckrin says Symbian will look not only at app marketplace real estate, but will use its own channels, sponsorships and events to promote apps.

Horizon will roll out its first apps this summer and plans to have 100 apps published by October.