Ferguson immediately joins as non-executive director before taking the reins from Ritson, who leaves his position on 6 August and will become a technical advisor to the company.
"As the company enters a critical phase in considering the commercialisation of its core assets in the Ruvuma Basin, the Horse Hill discovery and its exciting helium asset, I am delighted to be invited by the Solo board to become a non-executive director and chairman-designate,” Ferguson said in a statement.
“As the strategic focus of the board turns to how to provide a return to Shareholders through the monetisation of its assets and the eventual reinvestment of at least part of the proceeds, I look forward to bringing my own expertise to the Board to deliver this outcome."
Ritson, meanwhile, added: "I am very pleased to welcome Alastair to the board of Solo. Alastair's years of commercial and business experience, developing international gas projects in the Middle East, Asia Pacific and Russia, will strengthen the board and potentially expand the company's geographic reach.
“I look forward to continuing to assist the company in a technical capacity after my retirement from the board."