PORTLAND — The Oregon Liquor Control Commission has approved four software companies for tracking retail marijuana sales, a requirement of the state’s recreational marijuana licensees.

Oregon’s rules for recreational marijuana retailers require that they record their activity, and software systems approved Monday track sales, plants and harvests, among other functions.

The companies approved Monday are OMMPOS of Astoria; Flowhub, from Denver; Greenbits, from Portland; and Portland-based Odava.