The other 49 per cent of the shares of Torpedo7 will be retained by existing shareholders and settlement is expected to occur early next month.
Warehouse chairman Graham Evans said the move would offer customers "a retail experience when, how and where they want it across a broader range of products.
"The strategic partnership created by the purchase of a majority shareholding in Torpedo7 Limited is another example of our continued focus on the expansion of our multichannel business," he said.
Torpedo7 and its related companies had proven expertise in developing and growing online businesses, Evans said.
Torpedo7 will remain based in Hamilton as a standalone business and the management team will continue running its operations.
The Warehouse makes its half-year result announcement this Thursday. It shares were trading at $3.420 at 5pm on Friday.