Crocker National, the San Francisco-based parent company of Crocker National Bank, signed a definitive agreement with Midland Bank PLC of London on the previously announced plan for Midland to acquire the 43% of Crocker's stock that it does not now own . . . Miami-based Storer Communications said that it has completed the sale of two cable television systems in Northern California for a total of $11.5 million . . . Short interest on the the New York Stock Exchange for the month ended Jan. 15 fell 13.4 million shares to a total of 207.3 million shares . . . The American Iron and Steel Institute reported steel production for the week ended Jan. 19 rose to 1.550 million tons, up 1.2% from the previous week.