Later that day the company issued a clarification stating that Chellgren had violated a human resources policy unrelated to financial affairs. The company subsequently identified the policy in question as one that prohibits supervisors from dating or having romantic relationships with employees in their management chain.

An Ashland spokesman said the board of directors will work with Chellgren to develop a plan for naming a successor and making a smooth transition.

Stock analysts who follow Ashland said Chellgrens departure does not necessarily increase the likelihood of Valvoline being divested. Shells pending acquisition of Pennzoil-Quaker State would leave Valvoline as the last large U.S. passenger car motor oil business not owned by an oil company, and many lubricant industry observers have speculated that it might be an attractive pickup for an oil major, such as ExxonMobil. Chellgren, however, has maintained that Ashland was not looking to unload its motor oil business.

I would be very surprised if they sold Valvoline because its done a very good job in an incredibly tough market, said Bentley Offutt, of Offutt Securities in Cockeysville, Md. Its been one of the brighter parts of their business, and if you look at return on assets, its done very well. Its a cash cow and thats been [Ashlands] focus – to generate cash and buy back stock.

Fadel Gheit, a New York-based analyst with Fahnestock and Co., said that Valvoline might be an attractive acquisition. If you look at the acquisitions in the motor oil market, Valvoline is beginning to look like an orphan that needs a big sponsor, he said. If the price were right, I think a company like ExxonMobil would definitely buy it. So its not a lack of a would-be buyer.

But Ashland is a company that has been trying to reinvent itself the last few years, and Valvoline is the last pillar of the old companys legacy and strength. If Ashland sold Valvoline, it would be left with no identifiable market asset.

Analysts also agreed, however, that Valvolines future may be easier to divine once Chellgrens successor is named. The consensus: A hire from within Ashland would be likely to keep the motor oil business; an outsider would be more open to reconsider everything, including divesting Valvoline.

Wait and see who they pick, said an analyst who spoke on condition of anonymity. That will give you a better idea.

Among the most obvious in-house candidates are James J. OBrien and David J. DAntoni, two group directors who were shifted to different segments in November in moves designed to broaden their experience. OBrien, who had been president of Valvoline, became group operating officer for activities that include Ashland Specialty Chemical and Ashland Distribution. DAntoni had headed chemical operations and was named group operating officer for Valvoline and APAC, Ashlands highway construction business.