Texas investment firm Dimensional Fund Advisors has for the first time revealed a stake in Herbjorn Hansson’s Nordic American Tankers.

The Austin, Texas-based firm, which has close to $800bn in assets under management, said it had acquired 12.1m shares in the suezmax tanker specialist, good for a 5.8% stake.

The holding would place Dimensional neck-and-neck with giant US investment firm BlackRock, the world’s largest asset manager, as top holder in NAT.