NEW YORK (AP) -- Chemical makers, long corralled by fierce price competition, found a vehicle to pass on some costs over the summer as costs for the crude used in their products struck record highs.

They may be forced into retreat, however, amid the worst economic slowdown in a generation.

The prices chemical companies can charge for their biggest sellers, products used to make things consumers eye on store shelves every day, are under severe pressure.

Producers are grappling with "unprecedented," price declines, said Banc of America Securities analyst Kevin McCarthy said.

In the past 52 weeks, prices for benzene -- used to make nylon -- dropped 56 percent. Prices for propylene -- used to make packaging -- slipped 69 percent.

Falling demand and costs could lead to the "mother of all markdowns this holiday season" as retailers and manufacturers vie in a pricing tug of war, said Craig Johnson of President Customer Growth Partners, a consumer consulting and research firm.

Dow Chemical Co., one of the largest chemical makers in the world, said it may cut prices on some chemicals because the price of oil has crumbled, but other prices will remain unchanged.

"It all depends on the business, the product, the region," said spokesman David Winder. "All of this plays into it."

Midland, Mich.-based Dow, which makes products used to make items as varied as packing peanuts and diapers, said its energy and feedstock costs jumped 48 percent in the third quarter to $2.6 billion, the largest year-over-year increase in its history.

On Thursday, it's shares fell $2.09, or 11 percent, to $17.07 in a broad market sell-off.

DuPont says it'll also evaluate pricing business-by-business, but the cost for only a few of its most common raw materials has trended down after historic spikes.

Its shares fell 9.5 percent to $21.95.

Rohm & Haas, which is about to be bought by Dow Chemical, began indexing its prices to raw material and energy costs in May. The prices are adjusted monthly, a company spokeswoman said, and logically should drop as crude falls.

But everyone, from retailers to the companies that produce materials that go into consumer products, will likely be pressured.

"It's pretty clear the consumer expects prices to fall," said Ihsan Rahim, a petrochemical analyst at Platts, the energy information arm of McGraw-Hill Cos. "There's an incentive to keep prices higher, but you have to look at consumer demand behind it."

And whereas in the past falling raw material prices took a long time to trickle down to basic goods and services, that lag is slowly eroding due to the increased awareness, Rahim said.

Price comparison has become extremely common, and the "expectation is that supermarket prices will fall also," he said.

Some manufacturers in the chemical production chain have even been buying fewer commodities with the expectation that prices will drop further, he said.

"The question that a lot of people are asking is where the bottom of the market will be," he said. "I don't think we're close to the bottom yet."

All eyes now turn to the holiday shopping season, with many waiting to see how much the American shopper spends.

Said Rahim, "No one is going to buy now if they think things are going to get cheaper."