Co. and Mendelssohn & Co., was established in 1922. By the end of the 1930s, it had become the largest shale oil producer in Estonia. Around the company's mine and oil plant, the Kiviõli settlement (now town) was formed in the same way as the Küttejõu settlement (now district of Kiviõli) formed around the mine owned by Eesti Küttejõud. In 1924, the British investor-owned Estonian Oil Development Syndicate Ltd. (later Vanamõisa Oilfields Ltd.) purchased an open-pit mine in Vanamõisa and opened a shale oil extraction plant that was abandoned in 1931 due to technical problems. The Swedish–Norwegian consortium Eestimaa Õlikonsortsium (, ), controlled by Marcus Wallenberg, was founded in Sillamäe in 1926. New Consolidated Gold Fields Ltd. of the United Kingdom built a shale oil extraction plant at Kohtla-Nõmme in 1931. This facility continued to operate until 1961. In 1934, Eesti Kiviõli and New Consolidated Gold Fields established the service station chain Trustivapaa Bensiini (now: Teboil) in Finland, which in 1940 sold more shale-oil-derived gasoline in Finland than did the entire conventional gasoline market in Estonia. Since 1935, Estonian shale oil has been supplied to the German Kriegsmarine as a ship fuel. In 1938, 45% of Estonian shale oil was exported, accounting for 8% of Estonia's total exports. Although the price of oil shale-based gasoline was at least triple that of global gasoline prices, high production and bilateral agreements with Germany facilitated its export. In 1939, Estonia produced 181,000 tonnes of shale oil, including 22,500 tonnes of oil that were suitable gasoline equivalents. The mining and oil industry employed 6,150 persons. The oil shale-fired electrical power industry started in 1924 when the Tallinn Power Station switched to oil shale. In 1933, it reached a capacity of 22 megawatts (MW). Other oil shale-fired power stations were built in Püssi (3.7 MW), Kohtla (3.7 MW), Kunda (2.3 MW), and Kiviõli (0.8 MW). At the beginning of World War II, the total capacity of oil shale-fired power stations was 32.5 MW. Only the Tallinn and Püssi power stations were connected to the grid. On 9 May 1922 the first international discussion of Estonian kukersite took place at the 64th meeting of the Institution of Petroleum Technologists. Systematic research into oil shale and its products began at Tartu University's Oil Shale Research Laboratory in 1925, initiated by professor Paul Kogerman. In 1937, the Geological Committee under the Ministry of Economic Affairs, and the Institute