(Adds Nielsen statement, share reaction)
By Liana B. Baker and Joshua Franklin
Feb 8 (Reuters) - A private equity consortium led by Blackstone Group LP and Hellman & Friedman LLC and a group that includes Advent International and Goldman Sachs Group Inc's buyout arm have advanced to the second round of bidding for Nielsen Holdings Plc, people familiar with the matter said on Friday.
Nielsen said in September it would expand a review of strategic alternatives to include a sale of the entire television ratings company after coming under pressure to do so from hedge fund Elliott Management Corp, which in August reported it owned up to 8.4 percent of the company's shares.
Private equity firms Apollo Global Management LLC and Bain Capital LP also went to the next round of bidding in the Nielsen auction, which is expected to be completed by March, the sources said.
No deal is certain, cautioned the sources, who asked not to be identified because the matter is confidential.
"The Nielsen strategic review includes a broad range of options, including continuing to operate as a public, independent company, a separation of either Nielsen’s buy or watch segment, or a sale of the company," a spokeswoman said in a statement.
"There can be no assurance that this review will result in a specific transaction or other alternative. The company will provide updates on the review when it determines that further disclosure is appropriate or required."
Blackstone, Apollo, Advent, Goldman Sachs and Bain all declined to comment, while Hellman & Friedman did not respond to a request for comment.
Nielsen shares were up 3 percent at $26.32 on Friday, giving the company a market capitalization of $9.3 billion.
Nielsen, best known for providing audience figures that are used to determine advertising rates for TV commercials, has been seeking to adapt to the media industry’s shift to digital advertising and video consumption on mobile devices.
Before exploring an outright sale, Nielsen had said it was only exploring a sale of its "buy" segment, which provides marketing data on customers' purchases, and not its "watch" segment, which offers viewership and listenership data and analytics across TV, radio, online and mobile devices.
Nielsen, which has a debt pile of about $8.6 billion, almost as much as its market value, faces competition from start-ups using automated content recognition (ACR) to track viewing habits via mobile devices and smart TVs. It acquired Gracenote in 2017 in a bid to bolster its ACR capabilities. (Reporting by Liana B. Baker and Joshua Franklin in New York; Editing by Susan Thomas and Jeffrey Benkoe)