Seven & i Holdings Co, the world’s largest convenience store operator, is betting $21 billion on the future of quick-stop shopping in the US, reviving a once-abandoned deal to make sure the target didn’t fall into the hands of a competitor. The global operator of the 7-Eleven franchise agreed to buy Marathon Petroleum Corp’s gas-station business, adding 3,900 Speedway outlets to clinch a dominant position of almost 14,000 stores in the US and Canada. Seven & i pushed ahead despite the uncertainty of the pandemic and investor pessimism. Its shares declined 4.8 per cent in Tokyo on Monday. Marathon rose