Shares of US Supermarket chain Safeway (NYSE:SWY) jumped 24 percent on Thursday after Empire Co. agreed to buy the firm's Canadian operations for $5.7 billion.

Empire already owns the Sobey's grocery chain in Canada.

"The proceeds from this transaction are expected to be used to pay down $2 billion of debt, with the majority of the remainder to be used to buy back stock," Safeway said in a press release.