Americans experienced a slight increase in prices at the supermarket during the third quarter of 2000, according to the American Farm Bureau Federation's Marketbasket Survey. The latest informal survey shows a 23-cent increase in selected grocery items from this year's second quarter.

Shoppers paid $33.60 for 16 selected items during the third quarter. It marks the highest average recorded since the survey's inception in 1989. Still, this quarter's average is just $5.10 higher than the inaugural average of $28.50.

The 23-cent hike from last quarter's $33.37 average marks the seventh straight year when an increase occurred in the third quarter. Last year's third quarter experienced an 87-cent jump.

"The third quarter is typically the time of year when people use many of the products on the survey to cook outdoors," said AFBF economist Joe Miller. "Demand for many of the items on the survey tends to increase, and supplies tend to be lower during the summer months. Prices tend to reflect this."

Of the 16 items on the survey, eight increased in price. A dozen eggs experienced the largest increase, jumping 12 cents to 97 cents. This increase was expected, as egg prices fell drastically during the second quarter because of overproduction. With production cut back, supermarket prices have inched up this quarter to adjust for the smaller supply.

A pound of sirloin increased 10 cents to $2.65, while a pound of ground chuck jumped 9 cents to $1.90.

"Typically, you have the highest demand for beef products during the summer months in part because of cooking outdoors," said Miller. "And, we didn't have as much beef marketed this summer. We may see prices hold steady or possibly go lower this fall because of an expected increase in supply."

Other increases included mayonnaise, $2.90 per 32-ounce jar, up 7 cents; potatoes, $1.61 per 5-pound bag, up 5 cents; bacon, $2.77 per pound, up 2 cents; whole fryers, 97 cents per pound, up 2 cents; and vegetable oil, $2.16 per 32-ounce jar, up 1 cent.

Six items decreased in price, including a pound of pork chops, which fell 10 cents to $3.05. Other decreases included corn oil, $2.36 per 32-ounce jar, down 5 cents; cereal, $2.87 per 10-ounce box, down 4 cents; apples, 93 cents per pound, down 4 cents; flour, $1.40 per 5-pound bag, down 1 cent; and white bread, $1.19 per 20-ounce loaf, down 1 cent.

A gallon of whole milk, at $2.72, and a pound of cheddar cheese, at $3.15, remained unchanged from last quarter.

AFBF, the nation's largest and most influential farm organization, conducts its informal quarterly Marketbasket Survey to help track retail food prices to ensure they are in line with prices received by the nation's farmers and ranchers. While grocery store prices have increased for the most part during the past year, the farmers' and ranchers' share has actually dropped. The farm value of each food dollar spent in the United States is approximately 21 cents. Labor, at 38.5 cents, is the largest component of the consumers' food dollar.

Volunteer shoppers from 31 states participated in this latest survey, conducted in mid-August.