As broadcast executives gathered in a convention hall here recently to pay homage to trash TV, Michael Landon sat in a nearby coffee shop, trashing Geraldo Rivera.

Landon's bitterness toward Rivera goes beyond his distaste for the type of schlock TV the former ABC Newsman has come to epitomize.What really distrubs Landon most is the potshot Rivera took at Landon's wife during an interview with the 52-year old actor's ex-wife.

"It's bad enought to encourage this kind of thing, but...he's talking about people he doesn't know in a situation where a lot of children are involved," said Landon, who is the father of nine.

After listening to the "evidence," Rivera insulted Landon's current wife.

"He calls my wife-who happens to be the sweetest and nicesst person I have ever met and who ia adored by all the children-an air-headed bimbo."

Not about to let the comment go unchallenged, Landon poked back at Rivera on his "Highway to Heaven" series.

In a story about a couple of high school journalists who make life miserable for a school-bus driver accused of molesting a student, Landon gets his revenge.

As the angel on the show, Landon prohibits the school reporters from publishing the story because there is no evidence.

One of the students responds: "Do you realize we can make a movie of the week out of this? We'll send this to Hollywood. They love this kind of (stuff). Why do you think they watch Geraldo Rivera?" Landon, who contributed the lines, is anxious for the episode to appear. But all of heaven and Earth will have to wait to see this disgruntled angel give it back to Rivera.

NBC pulled the 5-year-old series from the schedule before this particular program appeared. Instead, it will be seen this spring when the network shows the remaining 10 original episodes of the canceled program.

"I can't wait for it," Landon said, laughing.

Most actors cannot use national TV to announce their grievances, but Landon is no ordinary actor.

A mainstay of wholesome family entertainment since his "Bonanza" days, Landon has established himself as a major force in Hollywood.

Unlike others in his profession who simply act, Landon has attained much of his clout working behind the scenes.

Through his company, Landon has produced two of NBC's longest-running series: "Little House on the Prairie," which lasted seven years, and "Highway."

Landon's business prowess has earned him the distinction of being the only producer of a prime-time television series to turn a profit during a show's network run - a feat that has gone virtually unnoticed in a town where money is considered the highway to heaven.

He uses his name-recognition and his creative flair to his advantage. For instance: During last week's National Association of Television Program Executive's convention here - the world's largest marketplace for the buying and selling of syndicated shows - Landon greeted potential buyers of "Highway" reruns with handshakes, angels, a heavenly gospel group and a sax player.

The good-boy image he displayed on the sales floor and in his TV shows was noticeably absent a few hours earlier during a one-on-one interview.

Landon peppers his conversations with off-colored jokes - at the rate of about one a minute - that would make even Lenny Bruce blush.

Of course, Landon is in much more of a joking mood now without the heavy work load.

Looking tanned and relaxed after a family vacation in Hawaii, Landon expressed mixed emotions about whether he will return to series TV.

After 14 years on "Bonanza," and the last dozen on "Little House" and "Highway," he is certainly in no rush.

"I do have fun with what I'm doing, but it is a tremendous amount of work," he said. "This is the first time in my life when I haven't had to plan anything.

"When I was doing the series, the minute I wrapped, I was already having meetings to set up what scripts I was going to do for the next season. I've been doing that for a long time. Now, all of the sudden, I don't have that responsibility immediately, and it doesn't feel too bad.

"I thought it was going to be tough, but it's not. It's really kind of fun, actually."

The long hours Landon put into his work often left him feeling drained.

"I'm finally clearing my head out," he said. "When you're doing back-to-back episodes - and you're rewriting everything yourself, directing and editing on Saturday - I just couldn't get all of those things out of my head.

"The ideas were bouncing all over the place, and I couldn't even focus in on one thing. I'd sit and try to watch the news at the end of the day sometimes, and I would realize that I was going through all the shots that I made that day. Now I don't have that for a while."

In Landon's terms, "a while" is about a year - the length of rest he had between his previous series.

"I never wanted to come back immediately because it really wouldn't have given me enough time to think about it," he said. "It's easy to do, though. They'll come at you right away with lucrative offers. But I think you get hurt that way because you don't have enough time to really prepare what you want to do."

Since completing the final episode of "Highway" in early December, Landon has moved his office closer to his home. He wants to put together several projects - and he insists they won't all be family-oriented - so his former production team will have about six months of study work when they return.

Landon's concern for his crew is atypical of many Hollywood producers. In fact, the way he talks, one gets the impression that Landon feels more comfortable around the little guys than other producers.

He has always shunned the Hollywood scene, preferring instead to spend time with his family - which now includes two grandchildren and a third on the way.

On those occasional trips out of town to shoot on location, Landon brings his wife and youngest children with him.

When the show was filming in town, both Landon and his crew members would get home in time to eat dinner with their families.

"We never worked late," he said.

But the job got done - and under budget. Landon gave out $900,000 in bonuses to his crew last year, a feat he repeated each year the show was in production.

He also payed them for 12-hour days, regardless of how long they worked, to ensure productivity.

To show their gratitude, the crew took out a large help-wanted ad in an entertainment trade paper requesting a producer who would show as much concern about them as Landon.

In contrast to the kind words he had for his hard-working crew, Landon had only uncomplimentary things to say about the Hollywood establishment.

Landon insists that too much time and money are wasted in Tinseltown. He found ways of saving money by eliminating waste, trimming out luxuries like big trailers for the star's dressing rooms and people who don't do their jobs.

"I'm not frugal, just smart," he said. "I'm a worker, and that's what this business needs. It needs people who don't just have interviews, if you know what I mean. I see an awful lot of them in this town. While they're having the interview, there's nothing to shoot on the set."

His wrath is also reserved for TV producers who, in their zeal to cut costs, forced the unions to accept wage and benefit concessions - but not before a series of crippling strikes over the past few years.

Landon's firm was one of the first to sign independent agreements with the writers' and craft unions.

The producers' first concerted effort against the Screen Extras Guild is the hardest one for Landon to stomach.

"It's amazing how they start with the poorest people in the world and destroy them," he said. "People making $91 a day who are lucky to work three days in a week. Now these people work for $5 an hour. That's $40 a day for three days work.

"And these are the people they had to do it to. That's going to make a difference in the budget? It doesn't make any sense at all."

Although the "little people" in Hollywood are suffering, Landon said those at the top ranks of the industry continue to prosper.