(Adds context) LONDON, Feb 3 (Reuters) - Private equity company Carlyle Group will increase its stake in Varo Energy by buying out one of two other partners in the Swiss refining firm, the companies said. Carlyle is part owner of Varo with Dutch investment firm Reggeborgh and energy trader Vitol. Varo said Carlyle would raise its share by acquiring Reggeborgh’s interest. Varo owns Switzerland’s Cressier refinery and a majority share of the Bayernoil refinery in Germany. It also has marketing and storage businesses in France, Belgium, Luxembourg, the Netherlands, Germany and Switzerland. Marcel van Poecke, managing director and head of Carlyle International Energy Partners, said Varo was expected to expand “as it leverages its solid platform and further capitalises on the opportunities presented by the shift towards low carbon.” Varo was valued at about 2 billion euros ($2.4 billion) when it planned to list on the Amsterdam stock market in 2018. But the flotation was cancelled, with Varo citing market volatility due to tensions in relations between the United States and China at the time. ($1 = 0.8325 euros)