The property tycoon now controls 25.6m shares, or about 5.2%, of the drilling company, according to a regulatory disclosure.
The stake is worth around $370m based on the closing price of Seadrill’s shares of $14.34 each on Monday.
He controls the stake via a number of investment holding companies including Singapore-registered Shanghai Summit Pte.
Tong is said to be the seventh of nine children whose parents ran a grocery store.
