Just how creative were AOL's attempts to cajole customers to buy $1 billion in advertising they neither wanted nor needed?

So creative, according to federal officials, that even Scott Sullivan, the former chief financial officer of WorldCom who is now serving a five-year prison sentence for his role in the biggest accounting fraud in history, saw a sham.

"This has turned into a money-changing scheme, and it can't continue," reads a November 2001 email from WorldCom cited in a complaint filed in federal district court in Manhattan on Monday.

The email was written by Sullivan and sent to three AOL executives, said Scott Friestad, associate director of the Securities and Exchange Commission's enforcement division.

It has been six years since securities regulators began investigating AOL's attempts to parlay the creativity of the advertising industry to the rules of accounting.

Monday's lawsuit, expected to be the final chapter in a story that began during the dotcom bubble, accuses eight former AOL executives of committing fraud.

AOL Time Warner's former chief financial officer, John Kelly, will contest the allegations, along with Joseph Ripp, the former C.F.O. of the AOL division, and two others.

Kelly "flatly denies" the government's claims and questions the "significant length of time that has passed since the events in question," said his lawyer, Jonathan Tuttle.

Four others, including AOL's former controller, James MacGuidwin, agreed to settle without admitting or denying wrongdoing, though they will pay millions of dollars in penalties and face other sanctions.

AOL founder Steve Case and Bob Pittman, the former No. 2 of AOL Time Warner, are apparently safe. The S.E.C. has no plans to bring further complaints against the company, now known as Time Warner, or any former or current employees, Friestad said.

The commission had extracted a $300 million settlement from Time Warner in 2005.

The nexus of WorldCom and AOL was a new revelation from Monday's lawsuit.

In the arrangement that prompted a rebuke from Sullivan, WorldCom twice agreed to waive penalties that AOL owed on an unrelated contract. AOL employees, seizing an opportunity to generate revenue, pushed WorldCom to let it pay the penalties and then return the money by buying advertising that it didn't want, officials allege.

"If you want $17 million in advertising, then pay $17 million instead of the credit and we will place ads, even though we don't need them," a clearly frustrated Sullivan wrote, according to the S.E.C. "If you want $25 million in advertising, then pay $17 million instead of the credit, pay another $8 million and we will place the ads, even though we don't need them."

Friestad described the complaint as outlining "one of the most egregious accounting frauds in recent memory."