The Co-operative Bank joined a shareholder rebellion last week over "excessive" executive pay at Xstrata, voting against the miner for the eighth successive year.  The Co-operative asset Management was part of a revolt that led to Xstrata's remuneration report being endorsed by only 68 per cent of shareholders at its annual meeting last week. The Co-op, which manages ?21 billion in funds, criticised Xstrata for paying excessive bonuses during the downturn. Mick Davis, the miner's chief executive, was paid $9 million (?5.5 million) last year, up 17 per cent from $7.7 million the year before. Xstrata was one of seven UK companies shamed by the Co-op for consistently failing to address investors' concerns about corporate governance. The publication of the C