ECONOMY

T-bill yields were mixed.

The Treasury auctioned 13-week bills at an average discount of 7.06 percent, up from 7.02 percent last week, and 26-week bills at an average of 6.96 percent, unchanged from last week. The investment rate was 7.29 percent on the 13-week bills and 7.31 percent on the 26-week bills.

Hiring plans

of U.S. companies will be scaled back sharply to recession levels in the first quarter of 1991, particularly in the Northeast, according to a survey of more than 15,000 businesses by Manpower Inc.

Consumers

scaled back borrowing between July and September, but the delinquency rate on loans was unchanged, the American Bankers Association said. REGULATION New Jersey officials

expressed concern about the financial viability of Donald Trump's Taj Mahal but said it was too early to predict the casino resort's fate. COMPANIES Westinghouse

said 600 employees in its energy systems business unit will lose their jobs at the end of the year.

Plus System Inc. and Visa USA

agreed to provide cardholders with access to all U.S.-based automated teller machines in the Plus and Visa networks.

MCI Communications and Chrysler

will jointly market MCI's long-distance services to Chrysler's 5,300 dealers. INTERNATIONAL Japan

will allow foreign investors to purchase stock in Nippon Telegraph and Telephone, the world's largest telecommunications company.

Swissair and Singapore Airlines

said they will swap small equity stakes, creating closer working ties between the two carriers. CONTRACTS Boeing

received a $252 million contract for Army CH-47D helicopters and for Navy E-6A aircraft.

General Electric

received a $110.8 million Navy contract for ship fire-control systems.

Storage Technology

received a $52.3 million Defense Logistics Agency contract for tape library systems.

MCI Communications

and the state of Colorado reached a five-year, multimillion-dollar agreement for MCI to be communications carrier for 1,200 state agency locations.

Computer Sciences Corp.

received a $120 million General Services Administration contract to develop computer systems and software for business applications at GSA's Pacific Zone operations, which include the western states, Hawaii and Alaska. The company said the first year of the 4 1/2-year contract is worth $24.8 million.

American Capital and Research

of Fairfax said its ICF Kaiser Engineers unit got a "significant" contract from USS/Kobe, a venture of Kobe Steel and U.S. Steel, to reline a blast furnace. Terms weren't disclosed. PEOPLE John Phelan,

the retiring chairman and chief executive of the New York Stock Exchange, will join Merrill Lynch's board.