Six weeks after Jay Leno moved to primetime, NBC’s wait-and-see approach to his sinking ratings is testing the patience of affiliate stations across the country.

The Peacock network maintains that putting Leno on five nights a week will pay off when fresh episodes of his show go up against reruns on other networks, but so far Leno has been a disappointing lead-in for the late newscasts that follow him.

After a strong start, his program at 10 p.m. is down sharply from its premiere week and is drawing one-quarter fewer viewers than its scripted predecessors a year ago. This is having a ripple effect on the local newscast and late night.

Ratings for late newscasts at NBC affiliates in 44 of the top 56 metered markets are down this year, falling an average of 13 percent in the first four weeks of the season compared with a year ago. In 10 of the top 25 major markets, the numbers are worse, with New York down 22 percent, Philadelphia off 37 percent and Miami down 30 percent.

NBC argues there could more factors at work than Leno and points out that some stations, such as Detroit, are up this season. Still, ratings for NBC affiliates are down more than those of its competitors. ABC affiliates’ newscasts are down 10 percent, while CBS’ are up 8 percent.

“We believe in the combination of a bankable star like Jay Leno hosting an exciting, topical show five nights a week and are committed to continuing to engage with our affiliates in ways to make that relationship work,” an NBC spokesman said.

NBC says Leno is a long-term strategy that will play out over 52 weeks, and that most affiliates appear to be on board.

“Some of the significant dramas right now are going to run out of steam by December and be out until February,” said DJ Wilson, general manager at KGW in Portland, Ore. “There is a real opportunity for Leno to pop. We really agree that this is a marathon, not a sprint.”

However, there are signs of growing discontent, with some station managers becoming more vocal about their dissatisfaction. One manager said the clock is ticking and he gives Leno until next year to show improvement.

“I give them through February,” said the manager, who asked to remain unnamed for fear of reprisal. “I don’t think anybody is anxious to pull any triggers. Plan B is to give the 10 p.m. hour back to the affiliates.”

The Peacock has been languishing in fourth place for a while, and it’s been years since it had a strong scripted lead-in at 10 p.m. In that time, affiliates have grown accustomed to doing the heavy lifting.

With Leno, NBC is easing the pain of lower ratings by giving affiliates additional commercial time to sell.

“The network reformed the programs so we get an extra bit of commercial inventory,” said Steve Baboulis, general manager of WNYT-TV in Albany. “The reality is our revenue in the 10 o’clock time period is up year-to-year. The difference is better inventory.” holly.sanders@nypost.com

