Montauk Renewables, which collects renewable gas and produces electricity at US landfill sites, says surging gas prices helped lift revenue by almost half in 2021, though profits came under pressure from costs related to its Nasdaq listing in that year.

Then known as Montauk Energy, the group listed on the JSE in 2014, when it generated $33.8m in revenue, having been spun out of black empowerment investment conglomerate Hosken Consolidated Investments, and now has an inward listing on the local bourse, where it is valued at R22.5bn...