Now his reputation is plumbing new depths as the US stock market regulator, the securities and exchange commission, begins an investigation of AOL for "unconventional" accounting practices.

The advertising deals done by Mr Pittman and his commercial team - branded "science fiction" by an AOL source quoted in the Washington Post - were aimed at boosting AOL's short-term revenues in the face of a disintegrating ad market.

According to the Post, which published its investigation of AOL's accounting practices last week, the ad sales team at the world's largest internet company went about booking revenues by almost any means as long as it showed up in that quarter's revenues.

To that end, the Post alleged, legal disputes were converted into booked ad deals, revenue was shifted from one division to another to boost the online business and ads were sold on behalf of online auction giant eBay and the cash booked as AOL's own.

The Post also claimed AOL Time Warner bartered ads for computer equipment from software giant Sun Microsystems and, in at least one deal, counted stock rights received from a cash-strapped company as ad and commerce revenue.

The SEC will consider whether any of these clearly unconventional deals violate accounting rules.

Meanwhile, AOL's new chief executive, Richard Parsons, who formally took control from the departing Gerald Levin earlier this year, told investors in a conference call yesterday that he plans to swear to the accuracy of company accounts under a new requirement being imposed on US executives on August 14.

Perhaps the only saving grace for Mr Pittman is that he is not the only person from the dotcom boom with the arrogance to believe he could rewrite the rules of accounting.

The fact Vivendi Universal's offices in Paris were recently raided by French regulators also concerned with financial accuracy shows there is a new and robust reality coming to bear on what was, in retrospect, a very unreal time.

Perhaps Mr Pittman and other dotcom executives could be forgiven for what the US federal reserve chairman, Alan Greenspan, called the "irrational exuberance" of the dotcom boom, if he was simply doing what everyone else was doing.

But even as the dotcoms that fuelled much of the late 90s advertising boom were starting to keel over in 2000, the pressure at AOL to close ad deals was particularly intense as the dotcom upstart sought to complete its takeover of Time Warner.

The AOL Time Warner chairman, Steve Case, who founded AOL, actually admitted last week "we took our eye off the consumer a bit because we were focusing on commerce and advertising".

Certainly in 2000, Mr Case's focus was on completing his takeover of Time Warner, which, in hindsight, was a master coup for an online company on the brink of the dotcom bust.

But the masterstroke has turned into a massive rout in AOL's share price, the departures of the merged company's first chief executive, Gerald Levin, and Mr Pittman, angry shareholders, disgruntled employees and now an SEC investigation.

Now the old media assets of Time Warner - which range from a music label and a Hollywood studio to HBO and its hit shows, such as The Sopranos - are again in the front seat at the firm.

Mr Pittman has gone, Mr Parsons comes from the Time Warner side of the business and a management revamp has elevated other old media hands into key decision-making positions.

Perhaps the most interesting question of all, at the end of a sad week for the company, is where does this leave Mr Case? He was the man who proselytised the internet like no other.

In the past, he convinced Bill Gates to put AOL on every Windows desktop and switched the firm's internet service provider business to flat-rate pricing.

Now he needs to return from his apparent semi-retirement and provide some practical and realistic solutions that will turn the idea of convergence into a workable business strategy.

But first Mr Case has to clean up the mess on his doorstep or, in Mr Parsons words (which will be easier for the City to understand), restore "investor trust".