Prime time is of the essence for...

Prime time is of the essence for Diane Sawyer.

The former “60 Minutes” correspondent, who signed a reported $1.6-million annual pact with ABC in February, joins Sam Donaldson as co-anchor of the network’s new “PrimeTime Live,” a news magazine that debuts Thursday at 10 p.m. on Channels 7, 3, 10 and 42.

Sawyer and Donaldson will host the series in front of a studio audience in New York. They will offer a mix of topical stories, investigative pieces and live reporting. As the title suggests, the programs will be live broadcasts, though viewers on the West Coast will see them on a tape-delay basis.

And with NBC’s “L.A. Law” and CBS’ “Knots Landing” as competition come fall, ABC has done no favors for Sawyer and Donaldson. But who knows? Perhaps their time has come. . . .