UNITED <UIL> PACT MAY LOWER NONCASH INCOME United Illuminating Co said that if the Department of Utility Controls approves an earnings stipulation agreement submitted March 18, it will reduce through accounting procedures its 1987 noncash earnings by 16 mln dlrs or 1.15 dlr per share. For the two month period ended February 28, 1987, it said the amount of the reduction would amount to 19 cts per share. Earlier, it reported net income for the two-month period of 23.1 mln dlrs of 1.51 dlr a share. United said the approval would lead it to an equity return level comparable with the electric utility industry average.