LONDON (Reuters) -British supermarket group Asda will extend a rapid online service for delivery within one hour to 96 stores after a trial exceeded expectations, it said on Friday. Asda, which trails market leader Tesco and Sainsbury’s in annual sales, had launched the “Express Delivery” service with a four-store trial in June. Rapid delivery is the latest frontier in the battle for grocery shoppers’ cash. A raft of new firms, including Weezy, Getir, Dija and Gorillas, are offering deliveries within 15 minutes of ordering, prompting traditional supermarket groups to rethink their business models. Tesco said on Wednesday it had expanded its “Whoosh” service to 60 shops. Asda’s service allows customers to order up to 70 grocery products from a range of over 30,000 for delivery within one hour if they live within a three-mile radius of a store. Delivery slots cost 8.50 pounds ($11.6) with no minimum spend requirement. “We are rolling out our Express Delivery service to almost 100 stores after a trial showed there was a clear gap in the market for a speedy delivery service offering our full online product range for delivery within one hour,” said Simon Gregg, Asda’s vice president of online grocery. Asda, owned by the Issa brothers and private equity firm TDR Capital, also recently extended its rapid delivery partnership with Uber Eats to over 300 stores. ($1 = 0.7354 pounds) Reporting by James Davey; Editing by Kate Holton Our Standards: The Thomson Reuters Trust Principles.