FILE PHOTO: The logo of the company of machinery Caterpillar (CAT) is seen at the site of a future urban project in Vina del Mar, Chile May 23, 2017. REUTERS/Rodrigo Garrido/File Photo

(Reuters) - Caterpillar Inc CAT.N said on Tuesday its Chief Financial Officer Brad Halverson would retire in early 2018, after spending nearly three decades with the world's largest construction and mining equipment maker.

Halverson, who is also the group president of the company, has served in the current roles since January 2013.

His retirement comes at a time when Caterpillar is fighting an IRS demand that it pay $2 billion in taxes and penalties for shifting profit to its Swiss unit to lessen its U.S. tax bill. (reut.rs/2uR9FiU)

Caterpillar said it would launch an external search to fill the CFO position.

Halverson joined Caterpillar in 1988 as an accountant.