Mills Fleet Farm is for sale.

The chain of giant, distinctively Midwestern general stores with orange silos, is facing opportunities and challenges too big for the third generation of family ownership, executives told employees.

“In the last several years business has been extremely strong and that strength has been enhanced by very successful new store locations,” the company said in a statement published by the Brainerd Dispatch on Thursday. “To ensure the strength of business going forward, the company is in the process of bringing in an outside partner to work with and enhance the current management structure.”

Chief Executive Stewart Mills III, grandson of the store’s founder, told the Dispatch that it is more than likely that his family will leave the business after the sale, though the Mills name may remain with the stores.

Mills, who ran unsuccessfully for Minnesota’s Eighth District congressional seat against incumbent Rep. Rick Nolan last year, told the Dispatch that the sale was not precipitated by his interest in politics. He recently filed candidacy papers to challenge Nolan again next year.

Mills did not return several calls by the Star Tribune on Thursday.

The company, started as Fleet Wholesale Supply in 1955, now employs more than 6,000 people in six Twin Cities metro stores and 35 stores throughout Minnesota, Wisconsin, Iowa and North Dakota. Another store under construction in Hermantown will open next year.

The chain is known for its giant store size, huge variation of merchandise — from obscure car parts to barn fans to children’s toys — and ubiquitous “we love it” commercial jingle. The orange silos became a signature feature starting in 2000.

Mills told the Dispatch that the retailer needs deeper pockets to expand. Besides adding additional stores, the company’s warehouse and distribution network needs updating. Mills hopes the chain could begin adding three to four stores per year.

“We have several interested parties, but we are sorting through those interested parties to make sure they are the best fit for us organizationally and also the best fit for our employees,” he told the Dispatch. “For the long term, this is what’s right for the business. This is what is right for our employees.”

The Mills Automotive Group is not part of the sale.