What happened

Shares of Nielsen Holdings (NYSE:NLSN) were up 9.3% as of 12 p.m. EDT Monday after The Wall Street Journal reported (may require subscription) over the weekend that activist investor Elliott Management is pushing the company to sell itself.

According to an SEC filing this morning, Elliott now owns 30 million shares of Nielsen, an 8.4% stake worth nearly $720 million as of this writing.

Stock market charts indicating gains

IMAGE SOURCE: GETTY IMAGES.

So what

According to WSJ, Elliott is partly justifying its push for a sale by arguing that Nielsen's "Buy" operation -- which focuses on consumer and retail behavior -- has "failed to keep up with competitors." 

Still, this shouldn't be entirely surprising. Shares of Nielsen are still reeling from a 25% single-day plunge late last month after the TV-ratings specialist posted second-quarter results that fell far below expectations. Nielsen also launched an "in-depth strategic review" for its "Buy" segment that day -- a move I wrote at the time could serve as an indication that it may restructure or divest the underperforming segment.

Now what

As it stands, investors considering whether to buy now should know there are no guarantees that Nielsen will cave to Elliott's pressure. In the meantime, Nielsen issued a statement insisting that it "welcomes the views" of shareholders and is continuing its strategic evaluation of the broader business. 

Steve Symington has no position in any of the stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. The Motley Fool has a disclosure policy.