Carbon-removal startup Terradot is acquiring competitor Eion, the two companies announced today. The sale was driven largely by big investors like sovereign wealth funds, which want to work with companies that can handle large contracts. Eion was simply too small, Eion CEO Anastasia Pavlovic Hans told The Wall Street Journal.

Both companies spread pulverized rocks on farm fields to absorb carbon dioxide from the atmosphere. Known as enhanced rock weathering (EWR), it speeds up a natural process and has the potential to be a low-cost way to remove carbon, but it requires large and distributed operations. The spread between what EWR companies would like to charge and what buyers would like to pay remains wide, according to a survey by CDR.fyi. 

California-based Terradot’s operations are centered on Brazil, where the company works with basalt as its mineral of choice, while Eion works in the U.S. and uses olivine. Terradot’s investor list includes Gigascale Capital, Google, Kleiner Perkins, and Microsoft, while Eion’s investors include AgFunder, Mercator Partners, and Overture.