Emerging energy group Renergen has inked a $25m (R365m) forward sales agreement that forms part of broader plans to allow investors to trade in the rare gas helium, intending to help bring price transparency to what is now an opaque market.

Renergen’s deal with Argonon Helium, a company formed in March for the transaction, will see helium traded like a cryptocurrency, using blockchain technology to create tokens that can be exchanged directly for the gas. Helium, unlike many other commodities, does not at present have a spot market, where assets are traded for immediate delivery. Instead producers rely on contracts...