LONDON.- Sothebys today announces that it will sell a newly discovered portrait by the great 17th Century Flemish painter Sir Anthony Van Dyck in its 6th July 2011 sale of Old Master and British Paintings in London. The intense and psychologically penetrating portrait of a young Carmelite monk is a hitherto unknown work, which Sothebys has discovered to have been painted by the youthful Van Dyck during the years he worked in Rubens studio. The painting is estimated to sell for £600,000-800,000. Early last year Sothebys Paris office did a routine valuation to appraise artwork, and noticed a painting of extraordinary quality which the family had owned for at least two centuries and which has always been known as the Confesseur de Rubens. Sothebys George Gordon,