T-Mobile Can’t Merge Without California’s OK, Regulator Says

California’s telecom regulator said T-Mobile US Inc. and Sprint Corp. can’t merge operations in the state until it blesses the deal.

The wireless carriers announced that they closed their deal April 1, even as their merger remains pending before the California Public Utilities Commission.

California was one of a handful of states that unsuccessfully sued to block the merger over concerns it would reduce competition and raise consumer prices. The utilities commission has been investigating similar issues and is on track to vote on the merger April 16.

The companies can’t combine businesses in the state “until after the CPUC ...