Founded in 2000, Rex Investment Limited is a medium-size, wholly-owned private company which owns Rex Energy Limited ; a power and utility company in Tanzania and also hold a rental property (Rex Investment Building) located in City Centre, Dar Es Salaam as one of its assets.

In 2013, Rex Energy was established and separated as an experienced turn-key renewable energy project developer and service provider that specializes in solar energy deployment. Its main function is to engage in large scale capacity solar projects in Tanzania e.g. mini-grid projects and solar farms.