WASHINGTON, May 20 (Reuters) - Nexstar Media Group NXST.O asked a U.S. appeals court late on Wednesday to expedite a review of a lower-court order that has halted its merger with rival broadcaster Tegna, saying the delay has cost it tens of millions of dollars in unrecoverable operational efficiencies.

A California judge on April 17 temporarily blocked the ‌$6.2 billion deal from proceeding, which has been challenged by a dozen state attorneys general and DirecTV.

The deal would create the ​largest broadcast ⁠station group in the United States, reaching 80% of households. Nexstar wants an appeals court to schedule oral arguments for August on the deal.