Google will to roll out a modular smartphone in January next year with segments that can be fitted like Lego pieces according to the tastes of users.

The basic kit developed under "Project Ara" will cost just around US$50, which is expected to have a huge impact a smartphone market currently dominated by high-end handsets from Samsung and Apple that cost hundreds of dollars.

The world's No. 1 Internet company unveiled the prototype at its Mountain View, California headquarters on Tuesday. It is tentatively called the Gray Phone.

Users first select an endoskeleton frame onto which rectangular modules with the different components are fitted. Once the modules are assembled, users simply flip on the power button and the smartphone is ready to use. New modules like a zoom camera can be added at any time.

Analysts expect the gadget to have a powerful impact on the industry. Koh Kwang-bum at consulting firm Accenture Korea said there it is "highly likely" that the Google phone will shake up the current market structure controlled by Samsung and Apple. "The present doctrine of offering finished products can't meet the constantly changing needs of consumers," he said.

Others are more skeptical. Kim Jin-hyung at the Software Policy and Research Institute said, "It's true that Project Ara is an innovative concept, but it won't be able to deliver a destructive blow to the market."

Industry insiders here were dismissive. A Samsung spokesman said, "Modular smartphones are likely to be inferior to finished products in quality, design and price the more sophisticated the smartphones are. They may appeal to some tech buffs but not to general consumers."