Barclays PLC (BCS) has been facing challenges to sell a stake in its U.K. merchant payments unit due to varied opinions on that business’ valuation, four people with knowledge of the matter informed Reuters.What Makes This Pursuit Challenging for Barclays?According to two of the sources, Brookfield was among the private equity firms that withdrew from bidding in recent months due to BCS’s high asking price. Other sources mentioned that negotiations have been complicated by the acquisition of Takepayments, o ...