In an unusual effort to reduce its bloated 1979 inventory, the financially troubled Chrysler Corp. is sponsoring massive tent sales this weekend at which the 15 Chrysler and Plymouth dealerships in metropolitan Washington will attempt to sell more than a thousand unwanted cars and trucks.

The tent sales will be staged on both sides of the Potomac - at Alexandria in Virginia and at Landover in Maryland. "It's like a department store sale," said Bernard Mullins, public relations manager for the auto company. "When you are overstocked, you have a sale - and that's what we are doing."

The sales extravaganza, a concept that Chrysler has used effectively in other parts of the country in recent days, is but one example of the company's efforts to stay afloat after suffering losses of $261 million in the first half of this year.

Three Washington area Chrysler dealerships closed their doors with little warning last week - an action that sparked sharp reactions from company employes and customers.

Many salesmen and mechanics at the dealerships feared that they might soon lose their jobs. Many customers expressed concern about what effect a possible large-scale collapse of Chrysler dealerships would have on the warranties of cars they had recently purchased. Still other customers flocked to the Chrysler showrooms in search of bargains.

Chrysler officials, meanwhile, attempted to stave off a panic by stating that the company's troubles were simply part of a temporary slump in the U.S. auto market.

"People haven't been buying cars [because of the gasoline shortage] so everybody in the industry has ended up with a large inventory," said Mullins. "And it's important to get the inventory down to make room for new models."

Mullins said the three local dealerships that closed last week had suffered financial woes for several months.

The other area dealerships opened as usual yesterday, and at least one claimed that its showroom traffic had improved.

"Freaky enough, [the financial problem] has stimulated business," said Dick Patterson, sales manager at Orbit Chrysler Plymouth in Accokeek in southern Prince George's County. "You have people thinking...the company is going defunct and they can come in and steal a car."

Patterson said sales during the last 10 days have increased by about 20 percent for his dealership.

Two customers who visited showrooms yesterday gave sharply divergent reasons for their presence, reasons that showed the paradox in the Chrysler situation.

"It's a buyer's market for Chrysler cars right now," said George Rahal, a stock broker shopping at Colonial Dodge in Rockville.

But at Glenmont Chrysler in Wheaton, a man drove into the lot with a quite different concern. "My concern is the warranty," said this owner of a 1979 silver Horizon. "Parts will always be available, somebody will buy that up. But the warranty...I just hope it will be honored."

Lawrence Kantner, an attorney for the Federal Trade Commission, agreed that "thre is always a supplier" of spare parts "when there is a market for the parts." He noted that some people are still making a comfortable living selling Packard parts.

Kantner advised car buyers to read their warranties carefully. He said only the selling dealer is required to perform warranty work on Chrysler cars. The only exceptions, he said, would be if the buyer moves or if he is on a trip more than 50 miles from home.

But Chrysler spokesman Mullins insisted that the company will stand by all warranties.

James Delgado, the sales manager at Colonial Doge, said he has received about 10 telephone calls each day from customers expressing similar concerns. He said they ask him where their cars would be serviced and what warranty service would be provided if Chrysler's financial position deteriorates.

But Delgado, like most other dealership officials interviewed yesterday, discounted the notion that the company's situation will worsen.

"There's no way Chrysler will go under," he said. "If Chrysler goes under, the whole world is in trouble, the whole economy goes under."

Adolph Schick, president of Al's Motors Inc. in Arlington, voiced the same faith in his company, saying: "I have full confidence in Chrysler."

As evidence of that faith, Schick said he has asked Chrysler to name his son, Rory, as the next dealer at Al's location. But Schick is candid about the financial troubles at his dealership, which he says is the oldest in the metropolitan area. "We're having a hard time, but we're keeping our heads above water," he said. Schick has stayed above water, he sayd, by trimming the payroll and expenses.

Despite the confidence of most dealers, however, fear spread through the ranks of employes at Chrysler lots this week. "They (the employes) wonder whether they're going to come to work and find a padlock on the door," said Ted Cooper, sales manager at District Silver Spring Dodge.

"I'm concerned," said Tony Watkins, one of Cooper's salesmen. "But I just don't dwell on it."

At the tent sale in Alexandria this weekend, Adolph Schick will have 65 to 70 cars ready for buyers to drive away. Schick said he will use "everybody I can muster" to help him hawk the cars. Everybody, in this case, includes his wife, his mother-in-law as well as most of his salesmen.

Schick said he will sell his cars at substantial markdowns. A $13,000 Chrysler New Yorker, for instance, will go for $2,200 less than the sticker price.

The tent sales will be held at the Landmark Shopping Center in Alexandria and the Capital Plaza Shopping Center in Landover. Chrysler officials said similar sales will be held this weekend in Seattle, Oklahoma City and San Diego.

Chrysler held its first tent sale in Minneapolis in late June and officials termed it a success.