NEW YORK -- Deutsche Telekom and AT&T are vowing to press ahead with the planned sale of the German company's T-Mobile USA unit to the U.S. phone giant despite concerns raised by U.S. authorities.

Nevertheless, AT&T Inc. said it plans to take a pretax accounting charge of $4 billion in the current quarter to reflect the break-up fees that would be due to Deutsche Telekom AG if regulators block the deal.

The two companies said they withdrew applications to the Federal Communications Commission regarding the merger and intended to seek its approval again "as soon as practical."

They took the step to consider "all options at the FCC and to focus their continuing efforts on obtaining antitrust clearance for the transaction from the Department of Justice," which filed a lawsuit in August to stop the deal, AT&T said in a statement.

Deutsche Telekom and AT&T made the move after the FCC chairman this week spoke out against the merger.

Safety investigation opened into Chevrolet Volt batteries

WASHINGTON -- Federal officials are investigating the safety of lithium-ion batteries in General Motors' Chevrolet Volt after a second battery fire following crash-testing of the electric car.

The National Highway Traffic Safety Administration said Friday that three Volt battery packs were crash-tested last week. In one instance, the battery caught fire afterward, and in another the battery emitted smoke and sparks.

Last May, a fire erupted in the battery of a Volt that had been damaged during a government crash test three weeks earlier. Last week's tests were an attempt to replicate the May fire.

The safety administration opened a formal safety defect investigation of the batteries.

General Motors officials said previously that government officials didn't follow the carmaker's protocols for storing post-crash batteries.

Commodities exchanges spur Illinois tax debate

CHICAGO -- The Windy City was shaped in part by commodities exchanges where contracts representing corn, wheat and hogs have changed hands for more than a century.

But two prominent exchanges are threatening to leave the state if Illinois doesn't change the way it taxes their trading.

State lawmakers are expected to convene Tuesday to discuss a deal that would appease CME Group Inc. and CBOE Holdings Inc., while meeting demands made by another Illinois mainstay, Sears. Those who back the tax breaks say they'll help keep jobs in a state whose unemployment rate hangs just above 10 percent.

Opponents say the state can't afford to make such deals and question whether the companies would make good on their threats or whether they are simply exploiting the state's weak bargaining position.

Makers of high-end cars chase Chinese wealth

MACAU -- China's super-rich want supercars. That's what the makers of the world's most exotic and expensive sports cars are hoping as they gather in Macau this week for the first Asian edition of Monaco's annual Top Marques show that began eight years ago.

The supercar companies are chasing growth in China, which is churning out scores of new millionaires each year and is home to the world's biggest auto market.

Ferraris and Lamborghinis sat alongside rare and beautiful automotive works of art from lesser-known marques like Italy's Pagani, West Richland, Wash.-based SSC and Sweden's Koenigsegg. They drew admiring looks from wealthy auto enthusiasts from China and other Asian countries.

Sales staff were hoping to sign deals with some of the 20,000 expected visitors.