LONDON, Dec 14 (Reuters Breakingviews) - A U.S. patent ruling will signal an intensification in the battle between Nordic warehouse automation group AutoStore (AUTO.OL) and its arch-rival Ocado (OCDO.L). Late on Monday, a U.S. International Trade Commission judge said the UK group had not violated AutoStore’s patents, enabling it to keep importing its robots for sorting deliveries into the country, and cementing its partnership with grocer Kroger (KR.N). It’s a blow to potential future growth for AutoStore, which made nearly a quarter of its revenue stateside in the three months to September. Ocado shares rose as much as 10% on Tuesday morning, while AutoStore’s fell around 13%, knocking some 19 billion Norwegian crowns ($2 billion) off its market capitalisation. At 36 Norwegian crowns per share, the SoftBank Group-backed (9984.T) company is still trading above the 31 Norwegian crowns price at which it was listed in October. However, the news highlights the weak protection that patents may offer rivals in this increasingly competitive sector. Even after Tuesday’s decline, AutoStore is valued at 50 times 2022 EBITDA after deducting net cash, Refinitiv data shows. That expensive valuation could look vulnerable as the robot wars hot up. (By Karen Kwok) Follow @Breakingviews on Twitter Capital Calls - More concise insights on global finance: Mr Big is smallest of Peloton’s problems read more Pfizer’s cure for post-Covid read more UBS’s French tax defeat tastes surprisingly sweet read more Credit Suisse belatedly unwinds Asian fiefdom read more Alibaba’s chip snub is blessing in disguise read more