Broker Vic DTVM and fund Geracao Futuro Lpar proposed Patricia Bentes as an independent member, challenging a list of 13 candidates presented by the company's controlling shareholders.

Vale said in the securities filing on Saturday the election of its board members may occur on Tuesday under the new cumulative voting system.

In March, Vale proposed enlarging its board by adding one independent member two months after nearly 300 people died in a mining dam operated by the company.

The proposed names include three independent board members and nine appointed by controlling shareholders. Vale's board of directors currently has 12 members.

Shareholders are seeking to strengthen Vale's new board by proposing executives with more experience in mining, sustainability and corporate governance issues.

Vale's controlling shareholders are Bradespar SA, Japan's Mitsui & Co Ltd and Litel, which holds the stakes of some Brazilian pension funds.

(Reporting by Carolina Mandl; Editing by Bill Trott)