LONDON (Reuters) -Barclays reported a 12% fall in first quarter profit on Thursday, as a squeeze on UK mortgage pricing, lower income from trading and a drought of M&A fees showed the difficulties it will face in delivering its first strategic revamp in a decade. The British bank reported pretax profit for the January-March period of 2.3 billion pounds ($2.84 billion), down from 2.6 billion pounds a year ago and narrowly above analysts' forecasts for 2.2 billion. Barclays is bidding to restore investor faith in its universal banking business model, after years of share price underperformance, clashes with activists over the role of its investment bank, and management turnover.