Internet advertising revenues are estimated to have reached new record levels of $4.2 billion in the third quarter, according to the Interactive Advertising Bureau (IAB) and PricewaterhouseCoopers LLP.

The third-quarter revenues were 33 percent more than the $3.1 billion in the year-ago quarter and 2 percent more than the second quarter's nearly $4.1 billion, according to the IAB and PwC. "Interactive advertising, with its eighth consecutive quarter of growth and the largest single quarter ever, is on pace for its biggest year," David Silverman, Partner, Assurance, PricewaterhouseCoopers, said in a statement.

"This growth follows the trend of where consumers are spending their media time and the unique ability of Interactive advertising to effectively target and monitor ad campaigns," he added.

Conducted by the New Media Group of PricewaterhouseCoopers, the "Advertising Revenue Report" was started by the IAB in 1996, and represents data from all companies that report meaningful online advertising revenues.

"The consistent growth of online advertising is a clear indication that marketers continue to embrace the true power of interactive advertising," said Sheryl Draizen, SVP, General Manager, IAB.