GREENVILLE, S.C. , Jan. 03, 2022 (GLOBE NEWSWIRE) -- United Community Banks, Inc. (NASDAQ: UCBI) (United) has completed its merger, effective January 1, 2022 , with Reliant Bancorp, Inc. (NASDAQCM: RBNC) (Reliant), including its wholly-owned subsidiary, Reliant Bank , which was merged with and into