South African billionaire Allan Gray has deepened his investment in companies controlled by Tor Olav Troim by boosting his stake in Borr Drilling.

Gray's Orbis Investment Management snapped up stock worth close to $2m in the Oslo-listed driller today.

The shares are worth $1.98m at Borr’s present trading price and the additional paper increases the investor’s stake in Borr to 5.02%, including convertibles.

According to Borr’s last annual report, its top shareholder was Schlumberger with over 14%.

Euroclear Bank, Folketrygdefondet, Troim’s Drew Holding and Goldman Sachs International were the next on the list.

Gray and his firms have not only been drawn to jack-up specialist Borr.

As TradeWinds reported a couple of weeks ago, Orbis had taken a leading stake in Troim’s Golar LNG.

Its funds now own more than 10.1 million shares of the LNG heavyweight, up from the 8.9 million disclosed in February, according to Securities and Exchange Commission filings.

Harvard graduate Gray is best known as one of the wealthiest people in Africa.