By Charlie Conchie Rachel Reeves must accelerate efforts to merge smaller pension funds and allow the country’s retirement cash to flow into British companies, the chief executive of Schroders has said. Speaking at the City A.M.Summit at Aquis this week, Peter Harrison, the outgoing chief of the FTSE 100 asset management firm, said the fragmented nature of the UK’s pensions market was stymieing investment and Westminster should step in to force “consolidation” of smaller retirement schemes. The comments come as Reeves and Keir Starmer hunt for ways to unlock more capital from pension funds and…