UPDATE 1-Southern Copper says will pay $0.34 dividend

(Adds quote from company, background)

MEXICO CITY, Oct 31 (Reuters) - Peruvian miner Southern Copper, one of the world's largest copper producers, announced on Friday it will pay shareholders a dividend of $0.34 per share on Dec. 5.

The company (PCU.N), which is a unit of Mexican miner Grupo Mexico (GMEXICOB.MX), also said its board has approved a plan to expand its share buyback program to $500 million from $300 million.

The buyback program "is consistent with a strategy of creating more value for shareholders," the company said in a filing with the Mexican Stock Exchange.

On Monday, the company reported its third-quarter net profit fell 33 percent from the same period a year ago.

Copper prices have more than halved since hitting record highs of above $4 per pound in July. (Reporting by Jason Lange; Editing by Bernard Orr)