Canadian convenience-store giant Alimentation Couche-Tard Inc. offered A$8.6 billion (US$5.8 billion) for fuel retailer Caltex Australia Ltd., sweetening its bid for about 2,000 sites as it seeks to broaden a global expansion.

Couche-Tard offered A$34.50 cash per share, higher than an earlier proposal of A$32 a share that was rejected as too low, Caltex said in a statement Tuesday. The fresh bid is 16 per cent higher than Monday’s closing price.

Caltex shares jumped 13 per cent, the most since 2002, to A$33.79 in Sydney trading on Tuesday.

Caltex, which earlier this week announced it planned an initial public offering of a 49 per cent stake in 250 retail freehold sites, said it was considering the proposal. Caltex gets about 23 per cent of its annual revenue from its convenience and retail operations, with its fuel and infrastructure business accounting for the rest, according to data compiled by Bloomberg.

In a separate statement, Couche-Tard said it made the original proposal on Oct. 11, and revised it on Nov. 18. The company said it holds a two per cent stake in Caltex.

Acquisitions have been a primary growth vehicle for Couche-Tard, owner of the Circle K chain of convenience stores. It has been active in M&A in North America amid a consolidation in the U.S. and Canadian convenience-store and fuel markets. Bloomberg Intelligence analyst Jennifer Bartashus wrote last month that as large targets in existing markets become less available, Couche-Tard was likely to pursue a deal in Asia.

“ACT’s management team has been looking into the Asia-Pacific region for several years as a potential market for our continued growth and we see many opportunities,” Chief Executive Officer Brian Hannasch said in the statement. “With Caltex, we see a potential opportunity to leverage our leading global position in the convenience retail market.”

Alain Bouchard, Couche-Tard’s co-founder and chairman, has gradually expanded the company, first in its home market, then to the rest of Canada, before entering the U.S. in 2001 and Europe in 2012. The company has a no-frills reputation, with top management known for visiting scores of stores to spot any weaknesses before making acquisitions.

Couche-Tard has more than 16,000 stores worldwide, according to its website.