The Securities and Exchange Commission on Thursday said that it had opened and closed a preliminary inquiry into International Business Machines Corp. (IBM), whose stock has been dogged by concerns about its accounting.

The news reversed IBM share losses sparked by a newsletter report that the company was under SEC investigation.

In a rare move, the SEC issued a statement that said "Regarding the reports of a preliminary inquiry by the SEC into IBM, the SEC staff opened an inquiry and closed it without action shortly thereafter."

After having fallen 5 percent during regular trading, No. 1 computer maker IBM shares jumped instantly on the news, recovering most of Thursday's losses.

Accounting newsletter SEC Insight Inc. said on Thursday it received a letter recently from the SEC saying that the SEC had conducted a preliminary inquiry of the company on Feb. 15.

An IBM spokeswoman declined to comment.

The SEC didn't say what the investigation involved.

The newsletter speculated that the timing of it indicated that it was related to a New York Times report criticizing the company for the way it accounted for a late fourth-quarter asset sale.

IBM has been under increased scrutiny in recent weeks. IBM will report on April 17 first-quarter earnings that fall far short of expectations. IBM warned on Monday its revenue would be about $1 billion less than analysts were expecting while earnings would fall short by about 20 percent.

It attributed the weak quarter to cuts in corporate technology spending. The warning came just a month after the company named Chief Executive Officer Samuel Palmisano to replace Louis Gerstner, who had been expected to retire.

IBM shares fell 5 percent, or $4.71 to $84.30 during trading, their lowest price since December 2000 while the American Stock Exchange Computer Hardware Index was off 2 percent.

So far this year, IBM shares have fallen 30 percent while the hardware index is off 8 percent. They fell sharply on Monday after the company shocked investors by saying it expected to post a massive first-quarter revenue shortfall. Shares closed 33 percent below their 52-week high of $126.39 on Jan. 9.

Plymouth, Minnesota-based SEC Insight has used U.S. "Freedom of Information" requests to unearth documents tied to probes of energy trading company Enron Corp., conglomerate Tyco International Ltd. and IBM software rival Computer Associates International Inc.