The administration, fearing a rerun of the ketchup-as-a-vegetable flap, is delaying until after the November elections new rules allowing use of high-sugar cereals in a nutrition program for about 2 million needy women and children.

The decision to delay the potentially controversial and less stringent rules for the program was made this week at a meeting of the Cabinet Council on Human Resources.

Cereal companies, led by General Mills Inc. and Kellogg Co., and chocolate manufacturers had pressed USDA hard for rules changes to allow more presweetened, high-sugar cereals and chocolate milk in WIC food packages.

According to sources, the council decided that proposed changes in the special food program for women, infants and children (WIC) could lead to a new round of embarrassing criticism similar to that after last year's ketchup caper.

"No question there was a political point to it," one official said. "The general thrust was that while there was some logic and science to loosening the sugar standard, this wasn't a good time to do it."

The administration, after undergoing considerable ridicule in Congress and in the news media, backed away from a cost-cutting proposal last fall that would have counted ketchup and pickle relish as vegetables in school lunches. The Department of Agriculture had intended to unveil its new WIC rules, undoing a series of standards left by the Carter administration, at a carefully planned briefing and news conference next week in Chicago.

The Cabinet council opinion means new rules would not take effect until at least the end of the year. USDA officials, including Mary C. Jarrett, assistant secretary for food and consumer service, declined to respond to a reporter's calls yesterday.

As a result of the delay, the cereal companies are talking about suing USDA. "We had hoped the department would let science prevail," one company's lobbyist said. "Our companies are darn well convinced we have a case for challenging the present sugar standard."

The delay also brought no joy to the other side, the antihunger lobby. For instance, Nancy Amidei of the Food Research & Action Center Inc. (FRAC) said the administration's nutrition ideas "seem to come from the ads on the Saturday morning cartoons."

Amidei said FRAC considers the pending changes in foods permitted in the WIC program contrary to congressional directives that the program be used to inspire health and nutrition education.

WIC is a politically popular, $900 million-a-year feeding scheme for about 2.2 million poor young mothers and children up to age 5 who are deemed to be nutritionally vulnerable. The foods they receive, high in protein and other key nutrients, are chosen for their beneficial dietary effect.

The WIC redesign under Jarrett's supervision has been billed as another of the administration's efforts to simplify federal regulation and give the states more flexibility in running programs such as WIC.

The regulations being rewritten were issued in November, 1980, by the outgoing Carter administration after several years of heated controversy and contention between food manufacturers and nutrition organizations.

Under the Carter plan, the rules were to have taken effect last November. About two thirds of the states, however, did not wait until that deadline before adjusting their WIC packages.

Meanwhile, the incoming Reagan administration suspended the rules for further study until this May. That suspension was extended until year's end while USDA derived its new approach.

One administration aide said, "The driving force was to give more flexibility to the states. It has always been a sincere desire on our part to simplify things . . . but a lesson we learned last fall from the ketchup thing was that tinkering can foul things up. It's better to go back to ground zero."

The now-delayed WIC redesign includes these changes:

* The Carter administration requirement that peanut butter, a high-protein food, be included in WIC food packages would be dropped. Beans also would be dropped, apparently after Mexican Americans argued that their basic diets already include beans and that they would prefer WIC offer them something different.

* Flavored milk--principally, chocolate milk--would be permitted in the WIC package. Nutritionists contended that sweetened milk added unnecessary sugar to young mothers' and childrens' diets and that, because it costs more than plain milk, would reduce the program's cost effectiveness.

But the biggest element in the controversy involves the amount of sugar in presweetened dry cereals. The Carter regulation instituted a limit of six grams per one-ounce serving that, along with a requirement that large amounts of iron be included, effectively excluded the high-sugar cereals.

Manufacturers, however, contend that there is no conclusive scientific evidence that the high-sugar cereals contribute to dental caries and dietary imbalance, as many nutritionists maintain.

The change crafted by Jarrett and USDA aides would eliminate the six-gram limit, while keeping the iron requirement, but also would give each state the option of allowing more or less sugar than that in its WIC package.