David Kappler will formally announce his intention to quit at the company's annual meeting in May.
He was brought in to guide the company after it floated on the stock exchange in 2004. He was previously chairman of music group HMV.
The news will heap pressure on a company that has seen 14 per cent of its market value wiped off following a poor trading update two weeks ago.
The Hovis owner needed to carry out emergency capital restructuring in the wake of the credit crisis and analysts say a £400m rights issue last year has left investors cold to the firm.
Kappler steps down after completing two terms of three years as chairman of the company. His relationship with Premier’s chief executive is believed to have soured in recent months.
Premier Foods will now begin the arduous process of searching for an experienced replacement chairman.