ECONOMY T-bill yields were mixed. The Treasury auctioned 13-week bills at an average discount of 6.52 percent, the same as last week, and 26-week bills at an average of 6.51 percent, up from 6.48 percent last week. The investment rate was 6.72 percent on the 13-week bills and 6.82 percent on the 26-week bills.

COMPANIES Alcoa said it will take a one-time charge of $275 million in reporting its 1990 fourth-quarter results. Loral Corp. said a high-speed, anti-radiation missile was successfully flight tested in California.

INTERNATIONAL Czechoslovakia has been offered $1.78 billion worth of loans by the International Monetary Fund, the first since the new government rejoined the organization in September.

EARNINGS K mart, citing the gulf crisis and weakening economy, said it expects earnings for the fourth quarter and fiscal year ending Jan. 30 to be below year-earlier levels.

PEOPLE Don R. Dixon, the former owner of Vernon Savings and Loan who faces sentencing next month on 23 counts of fraud, was reported in stable condition in a Texas hospital recovering from a heart attack. George H. Pfau Jr., a San Francisco investment banker, will be nominated by President Bush to be a director of the Securities Investor Protection Corp., a nonprofit corporation that insures the securities and cash in the customer accounts of member brokerage firms.

CONTRACTS TRW's command support division in Fairfax said that it will receive a $90 million subcontract from Computing Devices Co. of Ontario, Canada, for modernization of the Canadian military's tactical command, control and communications systems.

ODD LOTS The 12 largest airlines in the United States set a record in November for the fewest reports of lost baggage, and they had their second-best month for on-time arrivals and fewest traveler complaints, according to the Department of Transportation.