Trade commission officials find it difficult to prove that skewed search results harm consumers, sources say.

Division signals readiness to contest anticompetitive mergers in court.

Telecom underestimated government's concerns about its bid for T-Mobile.

Telecom underestimated government's concerns about its bid for T-Mobile.

Move to block takeover of T-Mobile suggests limited prospects for big telecom deals.

Getting the government to sign off may lead to more rules for telecoms.