Thor Industries Inc. said Tuesday its chairman and CEO Wade F. B. Thompson has stepped aside due to illness and has been replaced on an interim basis by the company's vice chairman.

The company, which makes recreational vehicles and buses, didn't give any details about Thompson's health.

Thompson, 69, has been president and CEO and a director since the company's founding in 1980. He also owns 28.4 percent of Thor stock, according to a regulatory filing last week.

Peter B. Orthwein, 64, a co-founder and director of the company, was named interim chairman, CEO and president. He has been vice chairman since 1986.

Thor, based in Jackson Center, has been hit hard by the recession, which undercut demand for RVs. In the fiscal year ended July 31, the company's sales tumbled 42 percent and profit fell to $17.1 million from $92.7 million the year before.

Last week, the company said sales in the quarter ended Oct. 31 were up 14 percent from a year ago, and Thompson said the company's backlog had grown during months when it usually declines, which he said showed strength in towable vehicles and motor homes.

Thompson and Orthwein founded Thor Industries with the acquisition of Airstream, an iconic brand that had hit a rough patch of road in the late 1970s. Within two years, Thompson and Orthwein cut costs and returned Airstream to profitability, then bought the Canadian company General Coach.

The company acquired bus maker ElDorado Bus in 1988 and Champion Bus in the 1990s.

Thor shares fell 43 cents, or 1.4 percent, to $30.48 in afternoon trading. After a slump that began in late 2007, the shares have rallied recently and are trading near their 52-week high of $32.98.