REAL ESTATE

AT&T; Corp. to Sell Buildings: The company agreed to sell its Chicago headquarters building and a connecting building, the USG Tower, to a Singapore pension fund for about $540 million, according to a person familiar with the transaction. The two buildings contain about 2.5 million square feet of space, making the purchase price $216 a square foot for the complex, built in 1989. Chicago office properties have been selling for about $157.50 a square foot, according to National Real Estate index, which tracks real estate price and rental trends in more than 50 markets. The sale is thought to be the biggest of its type this year. The complex is the latest trophy property to be sold by corporate America as businesses look to shed costly real estate assets with low returns.