UK Stocks-Factors to watch on May 24

May 24 (Reuters) - Britain's FTSE 100 index is seen opening up 6 points at 7,491 on Wednesday, according to financial bookmakers. * Soldiers will be deployed to key sites in Britain to boost security as the country raised its terror threat to the highest level of "critical" following a suicide attack in Manchester that killed 22 people, including children. * GLENCORE: U.S. grains trader Bunge Ltd said on Tuesday it was not in talks with Swiss mining and commodities group Glencore Pl