Timeline: Key events in AT&T’s bid to buy T-Mobile

Some key dates in wireless carrier AT&T Inc.’s effort to buy competitor T-Mobile USA, which was threatened Wednesday after the Justice Department filed a lawsuit to stop it from going through:

? March 20, 2011: AT&T says it is offering $39 billion in cash and stock to buy T-Mobile USA from German telecom company Deutsche Telekom AG. Such a combination would make it the largest cellphone company in the U.S. AT&T is currently the country’s second-largest wireless carrier, while T-Mobile is the fourth-largest.

Hoping to appease regulators, AT&T promised to spend an additional $8 billion to grow its ultrafast wireless broadband network in rural areas. The company now plans to cover 95 percent of the country with its so-called Long Term Evolution, or LTE, network, rather than 80 percent as was initially planned.

? March 28: Sprint Nextel Corp., the nation’s third-largest wireless carrier, urges the government to stop the proposed deal. Sprint Nextel argues that it would create a duopoly market with AT&T and Verizon Wireless ? currently the largest cellphone company ? taking the lion’s share of customers.

? April 7: In response to industry consolidation, the Federal Communications Commission approves rules that will require large wireless carriers to open their data networks to smaller regional carriers in areas where they don’t have their own systems in place. The big carriers will have to offer reasonably priced network access, and the FCC will resolve any disputes.

? July 20: The chairman of a Senate subcommittee on antitrust and consumer rights asks federal regulators to block the proposed deal. Sen. Herb Kohl, D.-Wis., says it would result in increased wireless service prices and fewer choices for consumers. He says there would be only three national cellphone companies left, and two of them ? AT&T and Verizon ? would control almost 80 percent of the market.

? Wednesday: AT&T promises to bring 5,000 wireless call center jobs back to the country if regulators allow the deal to go through. The company says that doing so won’t mean job cuts for call center employees that are already located in the U.S.

? Wednesday: The Justice Department files a lawsuit to halt the deal, arguing that it would raise prices for consumers and reduce their wireless choices. AT&T says it will fight the lawsuit and asks for an expedited court hearing.