(Reuters) -British electrical engineering firm Spectris Plc said on Monday it had ended talks regarding a possible bid worth 1.79 billion pounds ($2.37 billion) for Oxford Instruments, due to global economic uncertainties caused by Russia’s invasion of Ukraine. Shares in Oxford Instruments, a nanotechnology tools and services provider, plummeted nearly 22% on the news. Oxford Instruments last week said it had received a potential cash-and-stock offer from Spectris, valuing it at about 31 pounds a share. The Russia-Ukraine conflict has sparked a high degree of uncertainty in the global economy,…