Nokia ( NOK) can add another notch to its belt in the handset OS wars. The world's largest handset maker announced Friday morning that Samsung plans to license Nokia's Series 60 platform, a user interface built on top of the Symbian operating system. The Symbian OS is developed by company founded by a consortium of companies including Nokia, Ericsson ( ERICY), Motorola ( MOT), Siemens ( SI), Matsushita Electric Industrial ( MC) (owners of the Panasonic brand) and SonyEricsson. It's the third deal of its kind for Nokia, which is attempting to solidify support for its own handset software initiatives as it gets ready to battle Microsoft ( MSFT), which is developing its own versions of phone software. Details of the deal were not revealed. It's a symbolically important deal in part because Samsung, which currently commands about 9.5% global market share, according to recent Gartner Dataquest figures for the second quarter, is also one of the fastest-growing consumer electronics makers. The company has made tremendous strides in the handset market in recent years. It joins Siemens and Matsushita Electric Industrial, the other licensees of the Series 60 platform. Series 60 is designed for one-hand operation for next-generation phones that include color displays and ability to access next-generation wireless data services. Nokia is the global market share leader in handsets with an estimated 35.6% of the market (over 38% according to company estimates). Nokia expects its software to run on about 60% of the world's next-generation phones. It has been rumored for some time Samsung would join Nokia's camp after declarations of interest as early as the spring. But Samsung is by no means betting everything on Nokia's technology. According to recent FCC disclosures, Samsung is months away from selling phones based on the Palm ( PALM) OS and Microsoft's Smartphone 2002 and PocketPC Phone Edition platforms. As a Nokia licensee, Samsung will have access to flexibility to tinker with Nokia's source code. In recent trading, Nokia shares were up 58 cents, or 4.3%, to $14.