Mark also resigned from the board of Enron, which still holds a controlling stake in the water company. Azurix named John L Garrison, the company's president and chief operating officer, to replace Mark as chief executive. Herbert Winokur Jr, an Azurix director, was named interim chairman.

Since being spun off from Enron in 1999, the mighty Houston-based gas and electricity trader, Azurix's share price has tumbled to less than half of the $19 price it fetched last July when the company went public. After reporting earlier this month that net income fell in the second quarter from a year earlier, Azurix disclosed that negative foreign-exchange translations and disappointing growth overseas would likely keep it from reporting any "additional material earnings" for the rest of this year. Azurix reported net income of $14.4 million, or 12 cents a share, for the six months ended June 30, down from $20.5 million, or 29 cents a share, a year earlier.

The company also said it was cutting projections for full-year earnings to about $280 million, before interest, taxes, depreciation and amortization. Earlier guidance had ranged from $310 million to $340 million.

Azurix also said Winokur will assist the company's board in a review of the company's cost structure and strategy in an effort to improve its financial performance. Mark, who led Enron's international power-development projects beginning in the early '90s, established the water company two years ago following Enron's $2.2 billion acquisition of Britain's Wessex Water PLC, a water-distribution and sewage company.