PLEASANTON, Calif. - IronPlanet has formed alliances to auction used construction equipment from Caterpillar, Komatsu America International and Volvo Construction Equipment over the Internet.

The agreements give IronPlanet the exclusive right to auction used Volvo and Komatsu equipment online and a nonexclusive pact with Caterpillar for sales of its used construction equipment. Komatsu and Caterpillar will acquire equity interests in the online firm, and Volvo has invested $5 million in it, IronPlanet officials said.

Dealers of the three suppliers can buy and sell used equipment over the Internet site, and IronPlanet said it will provide buyers with a vast selection of used equipment from the companies.