Brendan Carr, the chairman of the Federal Communications Commission, said the inquiry could help Congress decide whether to continue funding local stations.

WASHINGTON —Federal Communications Commission chair Brendan Carr has sent a letter to the heads of PBS and NPR telling them the agency’s Enforcement Bureau is opening an investigation into the airing of sponsorships on public stations.

FCC’s Brendan Carr also suggests an investigation could be relevant to conservative congressional efforts to defund the public broadcasters.