COMPANIES in the British financial services sector cut jobs sharply in the final quarter of 1995, despite a pick up in optimism in the sector, according to a survey. Employment fell at its sharpest rate for two years and further, more pronounced job cuts are expected over the coming three months, reported the survey by the Confederation of British Industry and Coopers & Lybrand, the accountant and management consultant. It attributed the boost in business confidence to faster than expected growth and blamed the cutback in jobs on fierce competition.