Wal-Mart Stores Inc., the world's largest retailer, said it plans to open 50 discount stores and 180 to 185 supercenter stores next year in the company's largest-ever increase in new retail space.

Wal-Mart also said it will add 50 to 55 Sam's Club warehouse shopping stores in the United States.

More than half of the new supercenters, which are larger stores that sell groceries as well as discounted household goods, will be relocations or expansions of existing discount stores.

The plan represents 46 million square feet -- the largest increase in Wal-Mart's history -- which will boost its capacity by 9 percent over the fiscal 2002 total, said President and Chief Executive Officer Lee Scott.

Wal-Mart shares gained 71 cents, or 1.4 percent, to $50.47 in midday trade on the New York Stock Exchange.

Ulysses Yannas, an analyst for Buckman, Buckman & Reid, said the supercenters are attractive for Wal-Mart as it receives more than one-third of its sales from food, which increases traffic to the stores.

"They are just moving ahead further" against competitors, such as Kmart, Kroger Co. and Target Corp. , Yannas said of Wal-Mart.

The company said it will also open 15 to 20 Neighborhood Market stores in the fiscal year beginning in February, and 120 to 130 international units in countries where it already has stores.

Wal-Mart, based in Bentonville, Arkansas, said the plans for the new supercenters reflected consumers' acceptance of the format and financial results. It said it plans to open more units during the first half of next fiscal year compared with this fiscal year.

The company plans to build two regional general merchandise distribution centers, three food distribution centers and two fresh food distribution centers during the next fiscal year, adding almost 7 million square feet.