NEW YORK (CNN/Money) - Electronic Data Systems Corp. said late Tuesday that federal regulators have started an informal inquiry into the details that led up the company's stunning profit warning late last month.

The revelation came after the top executive at the No. 2 computer services company called the recent sell-off of its stock "a substantial overreaction" and outlined the company's plan to return to growth.

EDS said late Tuesday that it would cooperate with the Securities and Exchange's Commission's "informal inquiry" related to its recent surprise profit warning and other issues.

The company said the SEC has requested information regarding EDS' "purchase and settlement of forward contracts related to its common stock" and information regarding events leading up to the late September warning.

An SEC spokesman could not immediately be reached for comment.

Earlier, in a letter to shareholders, Dick Brown, the Plano, Texas-based firm's CEO, said he was "disappointed" that the company's recent earnings warning had taken such a large toll on its stock.

On Sept. 18, EDS warned investors that it expects third-quarter revenue to be down 2 to 5 percent, rather than up, as EDS executives previously had forecast. Earnings per share for the quarter are likely to range between 12 and 15 cents per share, far below the 74 cents per share previously forecast.

EDS shares rose $1.11 to $15.09 Tuesday, but the stock has lost more than 60 percent of its value, falling from $36.46 prior to the profit warning.

EDS blamed the shortfall in large part on a near halt in spending on information technology by large corporations. The company also said its exposure to certain high-profile bankruptcies, including US Airways and WorldCom, also contributed to the weaker-than-expected quarter.

But the magnitude of the shortfall also raised concerns about EDS' liquidity and its ability to seal future contracts, which often require large up-front investments. Some investors also expressed frustration with the company, which previously had assured them that its financial results would not be hurt by its exposure to bankrupt companies.

"We are deeply disappointed our lowered guidance for third-quarter earnings precipitated such a dramatic drop in EDS' stock price," Brown said in the shareholder letter Tuesday.

"While the market has spoken, you should know we believe it to be a substantial overreaction," Brown added. "Though many of our previous investors may have left us for the moment, our clients and our colleagues have not."

He stressed that EDS remains financially stable, with the resources to fund ongoing business and take on new clients.

Without providing specific details, Brown said EDS is reducing the company's expenses while better aligning earnings and cash flow "to reflect the realities of a market in which growth has substantially slowed -- and may remain soft well into next year."