March 16, 1999

Press Release

MBN RECEIVES OFFER FOR PORTER CHADBURN PLC

Middlefield Bancorp Limited ("MBN") announced today that a takeover bid has been launched for Porter Chadburn plc, a UK based company in the packaging industry in which MBN has an 8.3% equity position. The cash offer by Mail-Well Inc., a New York Stock Exchange listed company in the printing industry, is 38.5 pence per share, which represents a 61% pretax gain, or approximately $0.40 per MBN share on a fully diluted basis.

The Porter Chadburn investment exemplifies MBN’s strategy of investing in undervalued companies and pursuing activities to crystallize value not recognized by the market. In this case, MBN identified a UK to US arbitrage opportunity. At the time MBN accumulated its position in the company, its shares were trading on the London Stock Exchange at European price earnings multiples for packaging companies while most of its operations are in the United States, where price earnings multiples in this sector are substantially higher. Working closely with one of the top management teams in the flexible packaging industry, MBN pursued discussions with the management of Porter Chadburn. The objective of these discussions was to launch an offer for the company through a vehicle owned by the management team, MBN and institutional investors. This activity caused Porter Chadburn to seek a higher bid, the result of which is the Mail-Well offer.

MBN will continue to work with its packaging management team to execute a consolidation and rationalization strategy within the North American flexible packaging industry with the goal of creating one of the pre-eminent companies within this industry.

Middlefield Bancorp trades on the Toronto Stock Exchange under the symbol "MBN".

For further information contact:

Garth Jestley
President
(416) 362-0714