SEOUL--Samsung Electronics Co. said Monday it would postpone sales in Russia of a smartphone running a homegrown operating system called Tizen, dealing a fresh setback to the Korean smartphone maker's efforts to carve out a niche for itself in mobile software and services.

In a brief statement Monday, Samsung said that it was postponing the launch of the Samsung Z, which was slated to go on sale in Russia in the third quarter of this year.

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