TSB has narrowed the price range for its upcoming flotation to between 250p and 270p per share, valuing the challenger bank at 1.3bn pounds or more, according to sources familiar with the matter cited by Reuters.One source said the sale was "well-oversubscribed" within that range, the news agency reported. The challenger bank had previously been targeting a range of between 220p and 290p.-- More to follow --AB