NEW YORK :Canadian legal software maker Dye & Durham's second biggest investor, Plantro Ltd, has launched a proxy fight to elect new directors and is pushing for a sale of the company, according to documents seen by Reuters. Plantro Ltd, which owns 11 per cent of Dye & Durham, told the company on Monday that it nominated three director candidates to the 7-person board and that it requisitioned a special meeting where shareholders would vote on the nominees. Its nominees would bring expertise in