Plastics Capital, which owns a portfolio of small companies making niche plastic products has seen its share price plunge in morning trading after revealing falling profits and revenues and the departure of a founder shareholder from the board.The firm has four main subsidiaries: Bell Plastics; BNL; C&T Matrix; and Palagan. In the 12 months to the end of March, revenues fell 4% to £32m while profit before tax dropped 3% on the prior year to £3.765m.Unfortunately for the firm, which employs over 300 people, the stock price had fallen 17% by 10:42, indicating the market was troubled by something more than a relatively mild drop in revenue.Plastics Capital argues it has done well to keep the turnover reduction as low as 4%, with its factory in Thailand hit by floods, and the Japanese tsunami reducing demand in a key market.The Executive Chairman, Faisal Rahmatallah, said the board expected to "make good progress over the next year."In a separate and very brief announcement, the firm said non-executive director Arun Nagwaney, a founder shareholder of Plastics Capital, had left the board "owing to other business commitments".BS