Icahn, with 6 percent of Newell Brands shares, hasn't decided which side he's on

• In an SEC filing on Friday, Icahn discloses greater than 6 percent stake, says will talk to management and activist investor.
• Icahn had told CNBC earlier this month about the stake, but had not disclosed how much he had bought.

Billionaire Carl Icahn reported a greater than 6 percent stake in Rubbermaid parent Newell Brands, calling them undervalued, according to a regulatory filing on Friday.

The activist investor said in a filing with the Securities and Exchange Commission that he intends to talk with Newell management about ways to "enhance shareholder value." The filing also says Icahn expects to have additional talks with other fund manager, Starboard Value, about its proxy contest against Newell.

Earlier this month, Icahn told CNBC he had taken the large stake without saying exactly how much he had acquired.

Activists Starboard Value and Martin Franklin have teamed up to oust Newell's entire board. Icahn's filing on Friday said he hasn't decided whether he was going to support management or Starboard. "Although there is clearly no easy short-term fix for the Issuer, we believe there is an important role for our brand of activism," it said.