Englishman Lowes, currently with Pata Yamaha, is third in the 2019 standings going into the final two races in Argentina and then Qatar.
The 2020 season will be his seventh at WorldSBK level, having got his first taste of action when replacing the injured Rea in Czech Republic back in 2011.
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The 29-year-old will now ride alongside Rea, who confirmed his fifth world title last month, with Leon Haslam set to leave Kawasaki at the end of the season.
Lowes’ move comes after a strong year which has seen him make seven podiums to date, while he is also on a run of 14 top-seven results.
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He collided with Rea back in Jerez, an incident which saw the latter lose his podium finish.
Team boss Guim Roda said: “Our target is to ‘polish’ Lowes and try to make him a candidate for the title too. And he has a long career ahead.
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"He has shown very good skills during these years and for sure the potential is there. We’ll try to use all the tools at our disposal in KRT to help him show his best.”
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