Britain's FTSE 100 index is seen opening up 19 points at 7,427 on Tuesday, according to financial bookmakers. * BURFORD CAPITAL: Burford Capital began legal action on Monday against the London Stock Exchange seeking trading data it said it needs to investigate alleged manipulation of its share price. * ROYAL DUTCH SHELL: The governor of Nigeria's Rivers state said on Monday it had purchased Royal Dutch Shell's stake in a contested oil mining licence in the Ogo