Summary Box: Gov’t sues to block phone merger

RAISING AN OBJECTION: The U.S. Justice Department has filed a lawsuit to block AT&T’s $39 billion deal to buy T-Mobile USA.

THE CONCERNS: The government says that the combination of the No. 2 and No. 4 wireless carriers in the country would reduce competition and lead to price increases.

AT&T RESPONSE: The company plans to fight the decision. The company says the government has the burden of proving that it would harm competition.