US regulators on Monday announced fraud charges stemming indirectly from the merger of Time Warner and AOL, the largest union in US corporate history and a symbol of the dotcom boom and bust of the early part of this decade.

Eight former executives of the merged group were accused by the Securities and Exchange Commission of participating in a scheme to inflate internet advertising revenues at the merged AOL Time Warner by more than $1bn. The civil charges stem from claims that the eight artificially inflated online advertising as the dotcom boom evaporated, sustaining the internet company’s returns in the months leading up to and after the deal with Time Warner. The allegedly inflated earnings came at a time when investors, souring on the outlook for internet companies, were starting to question the wisdom of the merger, which handed AOL shareholders control of the more established traditional media group.