Aug. 5--John G. Drosdick's eight-year tenure as Sunoco Inc.'s chief executive officer spanned some of the most profitable years ever for oil refiners.

But as Drosdick steps down this week, the refining industry is back where it was when he joined the Philadelphia company as chief operating officer in 1996: in the doldrums, facing a round of lean years.

It was not supposed to be this way, according to industry bulls, who expected the fat profits of 2004 through the first half of last year to last through this decade.

Instead, refiners are reporting sharp year-over-year declines in profit. Their operating costs have soared while gasoline supplies are up, motorists have cut back on driving, and rising crude prices have outpaced price increases for key refined fuels.

Sunoco is to report second-quarter results tomorrow, and analysts are expecting it to rebound from two straight quarterly losses with a profit. If so, it will likely be a small fraction of the $509 million, or $4.20 a share, reported a year ago, when industry profits peaked.

Drosdick, a chemical engineer by training who began his career with Exxon Corp. 40 years ago, anticipated a downturn -- warning in 2004, for example, that while oil refining is "very seductive" during booms, it remains cyclical.

That stance earned him a reputation as a conservative executive at a time when rival Valero Energy Corp. became the nation's largest refiner through acquisitions.

"Drosdick always seemed to be preparing for that moment when the amazing profits would not be there," said Beth Evans, managing editor for Platts Oilgram News, a trade publication.

That time has come. "The Golden Age of refining is behind us, and we are entering the Dark Ages," Credit Suisse analyst Mark Flannery wrote in a note to investors last month.

Drosdick, who turns 65 this month, announced his retirement in July and has since declined to be interviewed. He is expected to remain chairman until the end of the year.

His successor, Lynn Laverty Elsenhans, will join Sunoco on Friday from Shell Downstream, where she overhauled the U.S. refining and marketing operations of Royal Dutch Shell P.L.C.

With Sunoco's shares off 59 percent since peaking in January 2006, some have speculated that Elsenhans could be coming in to execute an operations shake-up.

Adding fuel to that fire was the recent disclosure by Harbinger Capital Partners, a private-equity investor known as an agitator for changes at underperforming companies, that it had accumulated a 6.62 percent stake in Sunoco.

Sunoco already has said it is considering putting its chemical-manufacturing operations, which contributed about 7 percent of the company's revenue last year, into a joint venture.

In 2001, Sunoco doubled the size of its petrochemicals business with the $695 million purchase of Aristech Chemical Corp.