ASOS has sealed a deal for Topshop and other brands belonging to the collapsed Arcadia group.
The acquisition will cost 265 million pounds, or about 364 million dollars.
It includes some other brands such as Topman and Miss Selfridge.
But it does not include any of the related 70 stores, putting thousands of jobs at risk.
Philip Green's Arcadia fell into administration in November, becoming one of the biggest corporate victims of the past year's events.
Now the new deal is but one sign of how online retailers are in the ascendant.
ASOS rival Boohoo said Friday (January 29) that it was in talks to acquire other Arcadia brands including Dorothy Perkins and Wallis.
If a deal is struck there it would complete the breakup of Green's empire.
ASOS shares were up about 5% by midmorning Monday (February 1) in London.
Boohoo was up around one percent.