WASHINGTON — The Federal Communications Commission said on Friday that it would postpone until early 2016 a planned auction of airwaves now used by broadcast television stations for use by mobile phone companies.

The commission attributed the delay in part to a pending lawsuit filed by the National Association of Broadcasters, a trade group for the television industry, and to the need for more time to recruit television stations to participate.

The auction, previously set to begin in mid-2015, is likely to be the largest and most complicated sale of airwaves that the commission has undertaken. It involves a multistep process in which some broadcasters agree to give up their airwaves or move their signals to new spots on the electromagnetic spectrum in exchange for a portion of the proceeds of their sale.

Broadcast stations that do not participate in the auction could have their spot on the broadcast spectrum moved anyway, to help create contiguous blocks of airwaves for sale to mobile phone companies.