AMERICAN DYNAMICS <AMDC> TO SELL 51 PCT STAKE American Dynamics Corp and <Meridian Reserve Inc> said they signed a definitive agreement under which Meridian will buy 81.9 mln shares, or 51 pct, of American Dynamics' common stock. Under terms of the agreement, Santa Ana, Calif.-based Meridian said it will pay Columbus-based American Dynamics one mln dlrs in cash and notes over five years and about 500,000 shares of its common stock. Meridian said it has the option to issue an additional 1,500,000 shares of its common over the next two years in payment of certain of the notes. Meridian, an oil and gas company whose operations are primarily in Oklahoma, said the acquisition will increase its its consolidated assets to 30 mln dlrs and its contractually committed gas reserves to more than 40 mln dlrs at discounted present value. American Dynamics is engaged in gas gathering, transmission and liquids extraction, also in Oklahoma. The companies said they have five extracting plants and about 525 miles of transmission lines in five adjoining Oklahoma counties.