Activist investor Crystal Amber Fund has increased its stake in AIM-quoted Sutton Harbour to 5.08%. AIM-quoted Crystal Amber bought exactly 2.1m shares in the port operator, property developer and airline company on 25 February. Standard Life sold its stake of just over 2.1m shares on the same day. Crystal Amber has taken a number of high profile stakes, including in sports retailer JJB Sports. JJB accounts for around one-quarter of Crystal Amber's assets and it is currently losing money on this stake. Other investments have been more successful. The net asset value was 123.5p a share at the end of 2009, against a flotation price of 100p a share in June 2008. "The company's brief is to engage with investee companies and to promote active steps to correct undervaluation, thus realising value for Crystal Amber's shareholders", according to Crystal Amber's recent interim statement. Crystal Amber always meets with the management of investee companies. The share dealing was on the same day that Sutton Harbour released a trading statement and news of a link up between subsidiary Air Southwest and fellow UK regional airline Eastern Airways. The alliance will allow Air Southwest to join the Global Distribution ticketing system. Management hopes that this will boost revenues from travel agents and corporate travellers in the next financial year. The bad news is that the poor weather has hit Air Southwest's revenues. The property and port operations are trading well but it is unclear whether this will make up for the shortfall from the airline. Four Sutton Harbour directors, including chief executive Nigel Godefroy, acquired shares the day after the trading statement. A pre-close trading statement is promised at the end of March.