Nielsen Holdings NV (NLSN), the consumer research company controlled by private equity investors including KKR & Co. (KKR), fell the most since September of last year after sales missed analysts’ estimates.

Nielsen, which provides the audience data used to set TV advertising rates, dropped (NLSN) 5.7 percent to $29.65 at the close in New York, the biggest daily decline since Sept. 22, 2011. The shares are little changed this year.

Third-quarter sales rose 0.7 percent to $1.42 billion, New York-based Nielsen said today in a statement, reflecting a drop in the business that analyzes consumer spending. Analysts had forecast $1.44 billion, the average of 15 estimates (NLSN) compiled by Bloomberg. For the year, revenue excluding currency changes, will grow at the low end of the 5 percent to 6 percent range the company had predicted, Chief Financial Officer Brian J. West said on a conference call.

“Anytime a company misses revenue but hits earnings, investors are skeptical on the true organic pace of the business,” Todd Juenger, an analyst at Sanford C. Bernstein & Co. in New York, wrote in a note. “These flames were fanned by managements’ guiding to the lower end” of its revenue forecast for 2012 while projecting profit margin in the high end of the range. Juenger has a “market perform” rating on the stock.

Third-quarter profit excluding some items totaled 53 cents, beating estimates of 50 cents. Net income rose 2.9 percent to $105 million, or 29 cents a share.

For the year, Nielsen forecasts profit of $1.82 a share to $1.84 a share, exceeding the $1.81 average of analysts’ estimates. In July the company forecast $1.76 to $1.82.

In addition to KKR, Nielsen is controlled by private equity investors Blackstone Group LP (BX), Carlyle Group LP (CG), Hellman & Friedman LLC and Thomas H. Lee Partners LP. They control 57 percent of the stock, according to data (NLSN) compiled by Bloomberg.

To contact the reporter on this story: Rob Golum in Los Angeles at rgolum@bloomberg.net

To contact the editor responsible for this story: Anthony Palazzo at apalazzo@bloomberg.net