SAN FRANCISCO - Wal-Mart Stores Inc's chief executive kicked off a two-day meeting by telling Wall Street that the world's largest retailer has more room to grow, both at home and internationally.

I am competitive by nature and I want to win, CEO Mike Duke said in his opening remarks on Wednesday afternoon. There is no doubt in my mind that Wal-Mart will continue to win in retailing all around the world.

Wal-Mart is meeting with analysts on Wednesday and Thursday. Its shares were up 2 cents to $51.72 soon after the meeting began.

Duke said the company's expenses should grow less than sales. He said that Wal-Mart will work to improve its expense structure by driving more productivity and efficiency. (Reporting by Nicole Maestri, with additional reporting by Jessica Wohl in Chicago, editing by Gerald E. McCormick)