AOL's acquisition of The Huffington Post news and opinion website will trigger layoffs, the Internet company's chief executive Tim Armstrong said Thursday.

Armstrong, speaking at the paidContent 2011 conference here, did not indicate exactly how many people he expected would lose their jobs following the $315 million purchase of The Huffington Post or where they were currently working.

"My guess is there will be (layoffs)," Armstrong said in an appearance alongside The Huffington Post's founder Arianna Huffington. "There's no way around it for us and we just have to do it thoughtfully and carefully."

Armstrong also said AOL's acquisition would result in around $20 million in synergies between the organizations.

The Huffington Post buy was the latest high-profile purchase by Armstrong, who joined AOL from Google two years ago in an attempt to turn around a company whose name has become synonymous with the dotcom era's excesses.

In September, AOL purchased TechCrunch, a leading Silicon Valley technology blog. Other AOL properties include Engadget, Patch, Moviefone, MapQuest, Black Voices, PopEater, AOL Music, AOL Latino, AutoBlog and StyleList.

Huffington, whose personality and star-studded address book have been key to her site's success, was asked about The Huffington Post's controversial policy of using material from unpaid bloggers.

"The people who make that criticism completely fail to understand the sea change that has happened -- self-expression has become a tremendous source of fulfillment and entertainment for people," she said.

"We're getting literally hundreds of submissions a day... One thing we have to do is hire more blog editors because it's overwhelming."

The Huffington Post has attracted a strong following -- nearly 25 million unique visitors a month -- to its lively mix of news, entertainment, opinion and blogs submitted by academics, entertainment figures and politicians.

Aside from the high-profile celebrities, thousands of ordinary writers have also contributed to the site since its launch in 2005, most of them for free.

Huffington said she currently employs 143 editors and reporters "who are very well paid -- market rates and above -- with great benefits."

"These are the professional journalists we're paying," she added.

AOL, formerly known as America Online, fused with Time Warner in 2001 at the height of the dotcom boom in what is considered one of the most disastrous mergers ever.

It was spun off by Time Warner in December into an independent company.