NEW YORK (CNN/Money) - AOL Time Warner shares were jarred Friday following various news reports drawing attention to well-timed stock sales by top AOL brass, a cozy relationship with scandal-stained WorldCom, investigation of a separate deal with Qwest, and the possibility of another writedown.

AOL (AOL: down $1.46 to $12.61, Research, Estimates) shares fell more than 10 percent in midday trading on the New York Stock Exchange.

The Securities and Exchange Commission is looking at about $500 million in stock sales by 15 senior AOL executives between February and May 2001, CNNfn confirmed, citing sources familiar with the investigation. The agency is curious about the timing of the sales, which came as executives were making upbeat forecasts about the company's results and standing by the aggressive earnings estimates set in 2000.

Neither the SEC nor AOL would comment on the report, though AOL said it was cooperating with an ongoing SEC investigation of AOL's finances.

Included in the agency's examination, originally reported by the Financial Times, are $100 million in stock sales by Chairman Steve Case and $21 million in stock sales by Dick Parsons, who subsequently became CEO.

While there is no suggestion that the executives didn't believe their forecasts -- which would make the trades illegal -- the SEC nonetheless wants to examine the timing of the stock sales, especially in light of recent accounting snafus reported by the company, the parent company of CNN/Money.

The news couldn't come at a worse time for Parsons, who is trying to repair AOL's credibility with Wall Street after watching the company's stock plummet 67 percent in just the past year.

"If Case and Parsons sold stock knowing there was bad news coming out of the company, that would be ugly," said Youssef Squali, analyst with First Albany Corp., who added that, based on what he knew of both men, he doubted they did anything wrong.

AOL was recently ranked No. 3, behind Qwest Communications (Q: down $0.24 to $2.67, Research, Estimates) and Broadcom (BRCM: down $0.66 to $19.56, Research, Estimates), on Fortune magazine's "Greedy Bunch" list of 25 companies whose executives sold shares as the value of those shares plunged. According to Fortune, AOL executives sold about $1.8 billion in stock while AOL shares dropped. Case was the biggest seller, unloading $475 million worth.

The SEC also is focusing on $49 million in misreported revenue from the America Online unit. Most of that money was tied to advertising for an Internet carriage deal with WorldCom, CNNfn confirmed, again citing sources familiar with the investigation.

The Wall Street Journal, which first reported the story, said the deal was negotiated by David Colburn, the AOL deal maker who was summarily dismissed a week ago, and Scott Sullivan, the WorldCom chief financial officer who recently was arrested.

The New York Times reported that regulators are taking a similar look at an AOL deal with Qwest. Although there is no indication of any wrongdoing in either deal, regulators are likely taking a close look because of the high-profile nature of ongoing accounting problems at WorldCom and Qwest.

"Maybe everything's on the up and up," said David Burks, an analyst at J.J.B. Hilliard, W.B. Lyons. "But in light of what's happened, people are just going to be naturally suspicious when these names come up."

Neither WorldCom nor Qwest would comment on these reports, saying only that they were continuing to cooperate with ongoing SEC investigations into their finances. AOL also declined to comment on these reports.

"We're conducting an internal review into three transactions totaling $49 million, but we've declined to identify the companies [involved], given that we're in the middle of that review," AOL spokeswoman Tricia Primrose said.

In the meantime, the Wall Street Journal's influential "Heard on the Street" column suggested that AOL Time Warner may have to take another writedown as the value of its intangible assets continues to fall in the eyes of investors. Earlier this year, the company wrote off $54 billion in value.

First Albany's Squali said it was a bit premature to worry about the potential writedown -- which he said could amount to more than $5 billion -- since it likely won't be made until the end of the year and since the market already has discounted the value of AOL's assets.

"Anybody that looked at their balance sheet and at how much value they were placing on AOL understood there was a potential impairment charge there," Squali said.

In yet another news item, the company's CNN unit was highlighted in a Times article saying it now will start asking celebrities being interviewed about their health problems whether they received financial support from drug and health-care companies to publicize the company's products.

The paper reported CNN changed its policy after conducting a recent interview with actress Kathleen Turner during which her battle with rheumatoid arthritis was discussed. Turner receives support from drugmakers Amgen Inc. (AMGN: Research, Estimates) and Wyeth (WYE: Research, Estimates), the paper reported. The drugmakers together sell the arthritis drug Enbrel, but the drug was not mentioned by name during the interview.

The paper said the three morning news shows on ABC, NBC and CBS also are tightening their policy on asking celebrities about their ties with health-care companies.