Sainsbury's US supermarket chain Shaw's has followed its parent onto the Global Net Xchange (GNX).
Shaw's expects to generate close to US$2 million (£1.3 million) of savings from its first use of the online buying system.
The New England-based chain joined the scheme two months ago and is now sourcing carrier bags. A saving of US$1.8 million (£1.1 million) is likely.
A Sainsbury's spokeswoman said that Shaw's decided to join GNX after seeing the benefits to Sainsbury's in the UK and to groups such as Sears and Kroger in the US.
Sainsbury's has been using GNX for online auctioning since May 2000.
Separately, Shaw's has been on the acquisitions trail to bolster its position in its Northeast heartland.