(FORTUNE Magazine) – How long can chairman Phil Watts hang on at Royal Dutch/Shell? Ever since the company announced on Jan. 9 that--oops!--it had been overstating its oil and gas reserves by 20% for the past decade, there have been calls for his head.

With his shoulders in a Nixon-like hunch, Watts declared at a Feb. 5 analysts' meeting in London that he wasn't going anywhere for now (he's slated to retire in 18 months). But he didn't help his case with his unconvincing explanation of how Shell managed to overstate its reserves when he was running the company's exploration and production business from 1997 to 2001. Indeed, much of the overbooking occurred in Nigeria, where Watts was in charge of Shell operations in the early '90s.

The other bad news: Profits sank 19% in the fourth quarter, including a $984 million restructuring charge. "For the last ten years I thought this company was growing," says ABN Amro oil analyst Peter Nicol. "All of a sudden, it's sinking."

Former Shell executives say that Watts was never well liked--inside or outside the company. The betting in London is that he won't last the summer. --Janet Guyon