Steven R. Berrard will step down as co-CEO of AutoNation Inc.

Mr. Berrard, 44, says he'll devote full time to his New River Capital Partners venture-capital company. But he will remain an AutoNation director.

The firm is looking for a successor, a leader with a strong auto-industry background. Mr. Berrard says he'll stay on until his replacement is named. The executive recruiting firm, Korn/Ferry International, is AutoNation's headhunter.

W. Wayne Huizenga, AutoNation's other co-CEO and the founder of the dealership consolidating company, has not disguised his displeasure with the lagging performance of AutoNation stock.

Many of the early dealers, whom AutoNation bought out in 1996-98, accepted stock then worth $30-$35 a share. The price sank to a low of $10 in 1998 despite a wave of dealership purchases and AutoNation superstore openings. It rose to $17.13 in July.