"Anthem has started a complex takeover war in the US health insurance industry by making a $45bn approach for Cigna as the sector prepares for a wave of consolidation spurred by the introduction of 'Obamacare'," the Financial Times says.The Times has said that HSBC and JPMorgan are in talks to relocate parts of their business to Luxembourg "in what would amount to a huge coup for the tiny tax haven".According to a survey by the Institute of Directors and Cass Business School, security group G4S has the worst performing board of any British company, preceded by Sports Direct, RBS and Tesco, the Financial Times reports.David Cameron has ruled out holding a referendum on EU membership on 5 May 2016, the same date as the Scottish and other devolved elections, according to The Guardian.Greek prime minister Alexis Tsipras has accused creditors of "pillaging" Greece over the past five years and vowed not to give in to their demands, writes the Financial Times. He said it was now up to them to proposed a new rescue plan.BoE governor Mark Carney has turned down a pay rise for the second year, leaving his salary unchanged at £480,000, The Times writes.US fashion retailer Gap is to close 175 stores in North America, equal to a quarter of its domestic outlets, at a cost of $300m a year in addition to up to $160m of one-off costs, The Telegraph reports.Warren Buffett has bought a $500m stake in Insurance Australia Group as he targets a share of the growing Asian insurance market, The Guardian says.