LEAD: Debt Debt * Asarco Inc. has signed a $260 million, five-year revolving-credit agreement with a group of nine international banks.

LEAD: Debt Debt * Citicorp sold $50 million in 91-day commercial paper at an average rate of 8.674 percent, up from 8.559 percent last week.

LEAD: Debt Debt * Gulf States Utilities has established a $100 million secured credit facility with a group of financial institutions.

LEAD: Debt Debt * Alberto-Culver Co. has established a $100 million revolving credit agreement with five banks.

LEAD: Debt Debt * Keycorp, Albany, has filed for $400 million in debt securities.

LEAD: Debt Debt * Merrill Lynch & Co. is offering $225 million in 9.60 percent notes due 1995 at a price of par.

LEAD: Debt Debt * Enron Corp. filed a $400 million shelf offering.

Growing Debt Debt is also ballooning.

LEAD: Debt Debt * Citicorp plans to have its weekly auction of 91-day and 182-day commercial paper tomorrow.

LEAD: Debt Debt * Air Canada has secured an eight-year, $400 million credit facility in Europe from a bank syndicate.