And, the department said that any potential entry from a new mobile wireless telecommunications services provider would be unable to offset the transaction's anticompetitive effects because it would be difficult, time-consuming and expensive, requiring spectrum licenses and the construction of a network.

ENGADGET: US government files to block proposed AT&T / T-Mobile merger (update: companies respond)

The working group's proposal forbids the current practice of carrying forward gains and losses on hedges into the period of the transaction that they are designed to offset.

ECONOMIST: Accounting