CHICAGO — Morningstar Inc. said yesterday that the Securities and Exchange Commission has dropped its investigation into a 2004 episode in which the company failed to promptly fix incorrect data it published about a mutual fund.

The regulatory agency said it plans no action and considers the case closed, according to Morningstar.

The Chicago-based financial-research firm is "pleased with the SEC's decision," said chairman and chief executive Joe Mansueto, "and happy to put this matter behind us."

For influential Morningstar, which many investors count on to serve as an independent rater of the performance of mutual funds, the incident in question has always appeared to be more of an embarrassment than a serious regulatory or financial threat.

Early in 2004, Morningstar published incorrect data for the tiny Rock Canyon Top Flight fund for almost one month, listing returns that were better than Rock Canyon actually achieved. The discrepancy was apparently the result of miscommunication about the impact of a capital-gains distribution. Even after fund officials apprised Morningstar of the error, however, the company failed to correct the data for more than a week.

Investors didn't lose money as a result of the snafu. Rock Canyon Top Flight has said that during the time when the wrong data was posted, no investors put money in the fund.

Still, the SEC sent Morningstar a "Wells notice," which indicates that the agency is considering an enforcement action, regarding Morningstar's slow response in fixing the data. The timing of the episode was awkward as well, because news of the probe surfaced as Morningstar was preparing for its May 2005 initial public offering.

In the wake of the incident, Morningstar moved to bolster its quality-control measures. Nonetheless, less than a month before the IPO, the company disclosed that talks with the SEC on a possible settlement had ended unsuccessfully.

"We cannot predict what impact, if any, these matters may have on our business," it said.

Yesterday, after the Rock Canyon issue became moot, Morningstar shares rose 0.72 to $38.89 on the Nasdaq stock market. The stock has more than doubled since the company's $18.50-a-share IPO.

Morningstar still remains under investigation by New York Attorney General Eliot Spitzer, the SEC and the Labor Department on a different matter.

The regulators are reviewing the company's Morningstar Associates LLC unit, which helps clients design 401(k) retirement plans by recommending line-ups of mutual funds it thinks would be appropriate investment choices for a particular company's employee base.

The reviews are thought to center on whether the company received compensation from funds, and whether it can provide impartial ratings on mutual funds if it does so.

Spitzer subpoenaed Morningstar in December 2004, while the Department of Labor subpoenaed the company last May.

Spokeswoman Margaret Kirch Cohen said yesterday there was nothing new to report on those investigations and the company is fully cooperating with them.