In the ongoing game of Internet exec musical chairs, Greg Coleman (pictured here), who has been a top exec at both Yahoo and AOL, is poised to become president of the Huffington Post, as well as chief revenue officer, several sources said.

The deal for Coleman to come on board at the privately held online news site–which has grown significantly over the last year and just added well-known online media exec Eric Hippeau as CEO–came together only recently.

And it is not clear what the role of current Huffington Post Chief Revenue Officer James Smith will be going forward.

The Coleman hiring is most likely the work of Hippeau, who has known him from Coleman’s days as head of ad sales at Yahoo (YHOO). Hippeau has been on the board of the Internet giant for many years.

Hippeau was also a key player in the $5 million investment in the Huffington Post by SoftBank Capital in 2006.

He has also been a director on its small board, which also includes co-founders Arianna Huffington and Kenny Lerer, as well as Oak Investment Partners’ Fred Harman.

Oak recently added $25 million to the funding kitty at the Huffington Post, which is headquartered in New York.

The money will be used to expand the site into the local arena, investigative news, and verticals such as tech, a section set to debut Sept. 21.

It is all being done to build on what has been a strong traffic year for the Huffington Post, which claims it has over 21 million unique monthly visitors.

Nielsen Online has pegged that at the lower figure of 8.9 million, but reported that the Huffington Post was one of the fastest-growing, year-over-year news sites.

Despite that, the site still has not been regularly profitable, despite doubling annual revenue–mostly in advertising–to what some estimate to be about $8 million in 2009.

Presumably, goosing that revenue is what Coleman is being pegged to help do–and he certainly has a lot of online advertising experience, having made stops at a lot of Internet companies in the past few years.

He was head of advertising sales at Yahoo for seven years, after another long stint at Reader’s Digest. Yahoo’s ad business grew strongly under him.

But Coleman ran into Yahoo’s management buzzsaw after trouble hit the company in 2007. He was one of the first in a long line of execs to leave the troubled company, departing in one of its many controversial reorganizations.

He was soon running a Los Angeles-based start-up called NetSeer, which focuses on ad targeting.

He then headed to AOL in February to run its Platform-A division.

But when new management was suddenly put in place by Time Warner (TWX) in the spring, Coleman left after only a few months on the job.

After taking the summer off, several sources said, he has recently been looking at a variety of jobs.

That included MySpace, where former Yahoo colleague Wenda Harris Millard–now with Media Link–was hired recently as an outside consultant to help the News Corp. (NWS) social networking site rejigger its ad business.

The Huffington Post spokesman declined to comment when BoomTown inquired about Coleman’s hiring.

The large round by Oak, which was led by Palo Alto, Calif.-based venture capitalist Fred Harman, will give the popular online news and blog site a valuation of just “south of $100 million,” a source said.

The new funding, the Huffington Post’s third, will be used for expansion of its offerings and the hiring of editorial and business talent.

“There is an inevitable shift from offline to online with people increasingly getting their news media online, and this election proved how powerful the Huffington Post could be,” said Harman (pictured here), in an interview with BoomTown. “And I think the post-election perception of the Huffington Post has changed in the eyes of advertisers to being a key mainstream news site.”

Indeed, the Huffington Post–which is now billing itself as ‘”The Internet Newspaper”–has been hitting on all cylinders during the current election season.

And it hopes to continue building that momentum into the Obama administration, which will give the liberal-leaning site a lot of advantages in coverage.

The Huffington Post has also become a powerful news aggregator, much as the more conservative Drudge Report has, sending traffic all over the Web from its site by linking with a variety of online sites. It also has a strong offering of high-profile bloggers.

But the site’s leaders are also hoping its traffic strength will allow it to be as strong in arenas outside of its flagship political arena, including in business, local, “green” and investigative news.

It will also use the money to make acquisitions, the company said in a press release about the funding, which it put out this morning.

It’s certainly a long way from May of 2005, when its high-profile co-founder, Arianna Huffington, was roundly mocked for launching the site. Today, she has seen her power grow as the site’s traffic and influence have.

The site’s namesake operates out of her California-based office in Los Angeles, while the company has its HQ in New York.

The Huffington Post’s traffic in September 2008, for example, quadrupled from a year before to 4.5 million unique visitors, according to comScore (SCOR). That performance made it the No. 1 “stand-alone political blog and news site,” besting Drudge.

“The cycle of print media is accelerating downward and there are not as many companies with a balance sheet and focus to do it right online,” said Harman, who will join the Huffington Post’s board. “The news market is really up for grabs in a lot of ways…and it is a good time for those who are viewed as authoritative.”

But, like a lot of advertising-reliant businesses, the Huffington Post is also facing a tough market and must show it can compete under more dire economic circumstances and build a sustained and profitable business.

This slug of money should give it a lot of room to do so, said Harman, who has invested in several digital media companies, such as Demand Media and Federated Media. He was also one of the lead investors in aQuantive, the digital advertising business that was bought by Microsoft for $6 billion in 2007.

“Who knows how deep this economic situation is going to be,” said Harman, who noted that he and others kept investing in aQuantive through the last Web downturn. “But strong companies that keep investing through a bad cycle can emerge as winners.”

Previous investments in the Huffington Post have totaled about $12 million. That funding has come from Softbank Capital and Greycroft Partners, as well as seed money from co-founder Kenneth Lerer and former AOL exec Bob Pittman.

Funding reports about the Huffington Post appeared about a week ago in the Times of London, with the post claiming a $15 million investment and expansion into investigative and local news.

But the most detailed posts were done by paidContent, which was the first to name Oak as the new investor and said the round was $20 million.