COMPANIES 23 major corporations, including Amoco, Maytag, Nike and the Oliver Carr Co., have agreed to participate in an EPA program designed to reduce electricity use in the United States by 10 percent or more. Under the "Green Lights" program, companies will use energy-efficient lighting to reduce energy use. Sandoz Pharmaceuticals will stop requiring patients to buy expensive blood-monitoring services with its schizophrenia drug Clozaril, a move expected to cut the price by more than half. Instead, patients will be responsible for getting their blood monitored. Continental Airlines pilots agreed to a temporary pay freeze and other cost-saving measures. The airline is reorganizing under federal bankruptcy laws. Charter Medical Corp., which owns and operates 101 hospitals in the United States and Europe, said it has retained Kidder Peabody as a financial adviser to help it restructure more than $1.7 billion in debt.

EARNINGS Interco Inc. reported a third-quarter loss of $33.4 million. The company had a $58 million profit for the same period a year ago.

PEOPLE Enrico Pesatori, former head of Olivetti North America, has been named president and chief executive of Zenith Data Systems. Pesatori will also serve on the executive committee of Groupe Bull, Zenith Data's owner.

ODD LOTS The Treasury has sold 48,000 ounces of American Eagle gold bullion since Jan. 1, surpassing total December sales of 32,950 ounces. In the last two days alone, 26,500 ounces were sold. Private grain companies have sold the Soviet Union about two-thirds of the farm commodities authorized by the Agriculture Department last week in a $900 million U.S. credit deal, the government said. A Rhode Island lawsuit seeks the release of $276 million in frozen assets at Rhode Island Central Credit Union, one of 16 state banking institutions that remain closed. According the suit filed by a depositor, Gov. Bruce G. Sundlun violated state and federal constitutional standards when he closed 45 Rhode Island banks and credit unions.