December 2, 1997

Press Release

Middlefield Bancorp Limited has purchased 5,447,500 shares of Porter Chadburn plc, representing approximately 4.5% of Porter Chadburn's total ordinary shares outstanding. Porter Chadburn is headquartered in London, England and is engaged in the packaging industry, primarily in North America. Its shares trade on the London Stock Exchange.

Middlefield Bancorp Limited is a Canadian corporation engaged in merchant banking activities around the world. Managed by the Middlefield Group, Middlefield Bancorp is dedicated to the creation of shareholder value through the prudent selection, acquisition, management and sale of investment opportunities. Middlefield Bancorp's board of directors and management include highly experienced and successful individuals who have committed their own capital to the Company. Middlefield Bancorp's common shares are listed on the Toronto Stock Exchange under the symbol "MBN".

For further information, contact in Toronto, Canada:

Dean Orrico
Vice President
(416) 362-0714