Jan 5 (Reuters) - ExxonMobil Corp (XOM.N), the largest U.S. oil producer, said on Wednesday it had made two new discoveries in the Stabroek Block off Guyana"s coast, one of its top bets for production growth this decade. Guyana has been the scene of the world"s biggest offshore discoveries in years, with 10 billion barrels of recoverable oil and gas confirmed since it began production in 2019. An Exxon-led consortium is responsible for all output in the South American country. Exxon said the new discoveries, made at the Fangtooth-1 and Lau Lau-1 wells, will add to its previous resource estimates, without providing a volume update. The Fangtooth-1 well encountered high-quality oil-bearing sandstone reservoirs 11 miles (18 km) northwest of Exxon"s large Liza field. The Lau Lau-1 well has high-quality hydrocarbon-bearing sandstone reservoirs 42 miles (68 km) southeast of Liza, the company said. In September, Exxon announced a discovery at Pinktail in the Stabroek Block, also without specifying the size of the reserves. Exxon operates with a 45% stake in the 6.6-million-acre (2.7-million-hectare) Stabroek Block as part of a consortium that includes Hess Corp (HES.N), which has a 30% stake, and China"s CNOOC Ltd , which has 25%. Exxon had previously said it sees potential for installing 10 floating production vessels in the Stabroek Block. The first six such vessels could pump more than 1 million barrels of oil and gas per day (bpd) by 2027, Hess (HES.N) said in its most recent financial results. Exxon"s first FPSO produced 124,000 bpd in the third quarter of 2021. A second floating platform that can produce 220,000 bpd is set to start production this quarter. read more In December, Exxon outlined investments for a new onshore supply base, which will expand jobs and boost local fabrication amid government calls for delivering economic benefits to Guyana"s residents. read more The country"s parliament last month approved local content rules for oil producers and a sovereign wealth fund to oversee the country"s earnings from the oil bonanza. read more