By Kate Abnett BRUSSELS (Reuters) – The European Union’s plan for countries to buy gas jointly could maximise supplies and ensure better contract terms in the coming years, but is unlikely to help in the event of a sudden supply cut off, analysts and EU officials said. Pressure on Europe to secure alternative gas supplies increased on Thursday after Moscow imposed sanctions on European subsidiaries of state-owned Gazprom and Ukraine stopped a gas transit route, pushing prices higher. To become more independent of Russian gas and build a buffer against supply shocks, the EU in April launched a …