Ralcorp Holdings Inc. is exploring the sale of its remaining 20 percent stake in Post Holdings Inc., the cereal maker it spun off earlier this year.

The proposed sale of the stake, announced on Thursday, would be worth about $200 million at Post's closing share price on Wednesday.

Ralcorp has embarked on a restructuring program that will consolidate its various businesses with the aim of saving $26 million to $31 million in the year ending September 2013.

Ralcorp spun off its cereal business into Post Holdings after repeatedly spurning takeover offers from ConAgra Inc. last year.

Activist investor Corvex Management, which has been pushing Ralcorp to either sell itself, buy another company or change its strategy, had expressed concern that the company has had execution issues since the Post separation.

Ralcorp had to restate its financial reports for fiscal 2011 and the first quarter of fiscal 2012 to account for an additional impairment charge associated with the spin-off of Post.

Shares of Post Holdings closed at $29.49 on Wednesday on the New York Stock Exchange.