** U.S. regional TV operator Tegna's TGNA.N shares rise 9.3% to $21.90 premarket
** Federal Communications Commission approved $3.54 bln sale of TGNA to Nexstar NXST.O on Thursday
** "This transaction is essential to sustaining strong local journalism in the communities we serve" - NXST CEO Perry Sook
** Acquisition, if not reversed by courts, will expand NXST's presence to cover 80% of U.S. households
** On Wednesday, eight states filed suit in a U.S. District Court in California to block deal, stating it would lead to higher pay-TV prices and reduce jobs
** Up to last close, TGNA has risen 3.2% this year
(Reporting by Anhata Rooprai in Bengaluru)
((Anhata.Rooprai@thomsonreuters.com))