The UK Competition and Markets Authority (CMA) has announced plans to launch new investigations into big tech companies.The CMA will take advantage of the new "digital markets competition regime" which provides additional legal authority over tech giants.The investigations will focus on areas of digital activity and aim to ensure a level playing field for start-ups and scale-ups in the UK tech sector.This comes after a CMA study found that Apple and Google's mobile ecosystem policies in the UK were hindering innovation.