ECONOMY T-bill yields were mixed. The Treasury sold three-month bills at an average discount rate of 6.14 percent, up from 6.12 percent last week, and six-month bills at an average discount rate of 6.21 percent, unchanged from last week. The actual return to investors will be 6.32 percent for three-month bills and 6.50 percent for six-month bills. Downgrades of U.S. corporate debt outpaced upgrades in 1990 by a ratio of 4.4 to 1, Moody's Investors Service reported. It said the declines reflected "weakness in U.S. banking and the increasingly precarious position of highly leveraged companies in the industrial sector."

COMPANIES Citicorp plans to trim its operating costs $1.5 billion a year by 1993, as part of a plan to increase its capital by $4 billion to $5 billion, Chairman John Reed told securities analysts in New York. Security Pacific said it has held merger talks with Wells Fargo, a deal that would create the nation's second-largest bank group, but the contacts were discontinued and no further talks are underway. Chrysler said it has raised its goal for cutting costs to $3 billion from $2.5 billion. But Chairman Lee Iacocca said the change is not expected to result in a reduction in the size of the company's dividend unless the U.S. vehicle market worsens. Marriott Corp. of Bethesda signed a 10-year agreement to manage 15 golf courses that golfer Jack Nicklaus's Golden Bear International plans to develop in the United States and abroad. The Nicklaus firm, based in North Palm Beach, Fla., is considering sites in the Washington area, Baltimore, Northern California, Southern Florida and Atlanta. Signet Banking's debt rating was lowered by Standard & Poor's. S&P said the downgrades reflect the Richmond-based company's "high-risk loan profile with nearly 19 percent of loans in construction and 28 percent in total commercial real estate loans." Norfolk Southern's rail subsidiaries plan to spend $691 million on capital improvements this year, a 1.1 percent increase from the 1990 level, the company said. Pan Am warned creditors to expect a "substantial" loss for 1990. Chairman Thomas Plaskett, speaking at the first meeting of the carrier's creditors, also said Pan Am expects to submit a reorganization plan to bankruptcy court in the next 120 days.

INTERNATIONAL The Japanese economy continues to expand on the strength of corporate investment and personal consumption, the Bank of Japan said in a monthly review. It said the financial and exchange markets generally have reacted calmly to the gulf war. Toshiba said Synergy Semiconductor of California has agreed to share its advanced semiconductor production technology. Toshiba declined to disclose terms of the agreement. The Philippines said it will ask foreign bank creditors in New York next month to extend the country's $3 billion trade credit line. Manpower said it has taken steps to move its legal headquarters from Britain to the United States.

ACQUISITIONS Conoco signed an agreement with Wal-Mart stores to purchase Wal-Mart's nine convenience store and gasoline retail outlets in Texas, Missouri, Kansas and Arkansas. Terms were not disclosed.

COURTS The Supreme Court will hear an appeal by investors barred from taking tax deductions for losses incurred in a tax-shelter plan involving government securities. The case stems from a computer-generated investment program offered by First Western Government Securities, created in 1978 by former IRS agent Sidney Samuels.

EARNINGS Bell Atlantic said earnings rose 308 percent in the fourth-quarter and 22 percent in all of 1990. United Technologies reported an 8 percent drop in fourth-quarter earnings but a 7 percent increase in profit for all of 1990. Merck & Co. reported a 20 percent increase in earnings for the final three months of 1990. For all of 1990, net income increased 19 percent. Monsanto reported a 65 percent drop in fourth-quarter earnings and a 19 percent decrease in earnings for all of last year.

PEOPLE Susan Engeleiter resigned as administrator of the Small Business Administration effective in April. Engeleiter, 38, who took over the post after losing a 1988 bid for the Senate from Wisconsin, said she will return to the Midwest to take a job in private industry.

ODD LOTS Land in Tokyo's Ginza shopping district has been assessed at $252,000 a square yard, up 17.5 percent from a year earlier, the government reported. For the whole nation, land valuations rose an average of 38.1 percent in the past year, the biggest increase since a 40.2 percent jump in 1962. Pepsi ran the most popular TV ads of 1990, according to a consumer survey done by the research firm Video Storyboard Tests. Ads for Nike shoes came in second, followed by campaigns for Energizer batteries, Coke and McDonald's, which had ranked first in 1989.