Just a few hours after it announced its new flagship Galaxy 4 smartphone, Samsung on Friday confirmed that is readying a smartphone based on the Tizen operating system to be released in the second half of this year.

NTT DoCoMo, Japan's largest mobile carrier, plans to launchthe Samsung handset on its network by the end of the year.

"The Tizen phone will be out in August or September, and this will be in the high-end category," Lee Young Hee, executive vice president of Samsung's mobile business, said during an interview in Seoul. "The device will be the best product equipped with the best specifications."

Samsung, Intel, Sprint Nextel Corp., Panasonic, NTT DoCoMo Inc. and Vodafone Group Plc are among the 12 companies developing the open-source Tizen as an alternative to Google?s Android OS.

Android's share of the global smartphone market rose to 68.4 percent in 2012 from 48.7 percent a year earlier, according to a January report by Strategy Analytics. Android and Apple's iOS software combined for 87.8 percent of all smartphones shipped last year.

Tizen relies on the web platform HTML5 for application development, with the idea that developers won't have to recode their apps for the operating system. The Tizen Association promises that the release of the first Tizen handheld will be accompanied by thousands of applications.

The group last month released a software development kit and source code for a new version of the operating system. Tizen 2.0 includes a Web UI framework, software interfaces for hardware such as Bluetooth and NFC and core features including phone, calendar and a video player functions.

Huawei Technologies is also among manufacturers developing the Tizen operating system.

Tizen is one of several new challengers to the existing duopoly of Android and iOS. In addition to Windows Phone and Blackberry OS, open source offerings from Firefox and Ubuntu are also in the works.