The bathing suit, which is currently on display in a second-hand store in the southern Swedish town of Eslöv, will be sold to the highest bidder when the auction wraps up on Saturday, owner Zlatko Nedanovski told AFP.
He said the profits from the sale would be used to purchase cows for poor Indian farmers.
“Today we have enough for three cows,” he said, referring to a bid given on the first day of the auction on Tuesday.
Nedanovski, 32, said he hoped to raise enough to buy five cows, which at a price of 1,800 kronor (€190, $280) a head should cost a total of 9,000 kronor.
Kidman, an avid swimmer, forgot the suit at a pool she had reserved for her personal use in the southwestern town of Vänersborg during a 2002 stay in Sweden to shoot Lars von Trier’s “Dogville”.
Pool staff found the suit and handed it over to a local radio station.
Nedanovski then bought the swimsuit for 5,500 kronor.
“I have been in possession of this bathing suit for more than five years and … the time has come for me to pay my dues, for instance through a charitable project,” he said.
Nedanovski said he had been inspired by the “concrete” nature of the cow-buying project, which is run by the Swedish aid organization Erikshjälpen.