UPDATE 1-Brazilian power firm Cemig plans voluntary buyouts

(Updates with Cemig comment)

SAO PAULO, May 4 (Reuters) - The executive board of Brazilian power firm Cemig has approved a voluntary buyout program for up to 1,000 employees, according to an internal document seen by Reuters on Monday.

The buyouts are set to be effective starting in June, according to the document.

Cia Energetica de Minas Gerais SA, as the firm is formally known, confirmed the contents of the document to Reuters, emphasizing that the buyout is completely voluntary.

The firm did not offer a cost savings estimate, but noted that about 600 people signed up for a similar buyout program last year, saving the company nearly 150 million reais ($27.1 million).

The Brazilian state of Minas Gerais is Cemig’s majority shareholder.

$1 = 5.54 reais Reporting by Luciano Costa; Writing by Gram Slattery; Editing by Sonya Hepinstall