(Reuters) – British electrical engineering firm Spectris said on Tuesday it will sell specialist sensor maker Omega Engineering to private equity firm Arcline Investment Management for $525 million. Spectris, which last month ended its $2.4 bln pursuit of Oxford Instruments against the backdrop of the Ukraine crisis, also announced a 300-million-pound ($389.91 million) stock buyback. ($1 = 0.7694 pounds) (Reporting by Radhika Anilkumar in Bengaluru; Editing by Shounak Dasgupta)