UPDATE 1-UK Stocks-Factors to watch on May 26

(Adds futures, company news) May 26 (Reuters) - Britain's FTSE 100 index futures were up 0.03 percent on Friday ahead of the cash market open. * BARCLAYS: Britain's Serious Fraud Office said on Thursday Barclays and its former senior bankers will not know until around mid-June whether they face criminal charges over a 2008 emergency fundraising from Qatar. * ACACIA: Barrick Gold said on Thursday that two mines at its majority-held Acacia Mining, which account for some 6 percen