Rather than relying heavily on new Wal-Marts, executives are now more focused on squeezing sales and profits out of older ones.

The announcement, combined with the company’s decision to increase its share buyback, impressed investors, who sent shares of Wal-Mart up $1.87, or almost 4 percent, to $49.47.

By cutting back its expansion, Wal-Mart is following the advice that analysts have given the company for years: focus on obtaining the best possible return on investments, not just on growth for its own sake.

This year, rather than opening 265 to 270 stores, as Wal-Mart had previously planned, it will open 190 to 200, which will produce enormous cost savings.

For the next three years after that, Wal-Mart plans to open 170 supercenters a year — well below its average. Executives at the shareholder meeting strongly defended H. Lee Scott Jr., the chief executive of Wal-Mart, against charges that he had an improper business relationship with a vendor. The company also disclosed an increase in its stock buyback program and claimed early success in efforts to fix a wide range of problems in United States stores.

Reacting to allegations by Julie Roehm, a fired former advertising executive, that Mr. Scott bought boats and a diamond ring from vendors at discounted rates, Thomas D. Hyde, Wal-Mart’s corporate secretary, said, “Mr. Scott did not and has not committed ethical violations.”

“Wal-Mart’s ethical standards are equal to or more stringent than those of more retailers,” he added. “In my opinion,” he said, Mr. Scott “undernegotiates and overpays and leaves too much on the table when he buys things. He knows he lives in a fishbowl.”

In another nod to Wall Street, Thomas M. Schoewe, the chief financial officer, said Wal-Mart would buy back $15 billion worth of stock. Wal-Mart’s last buyback program was $10 billion. The move is expected to bolster earnings per share and, eventually, the stock price, which has languished for much of the year.

Wall Street has begun to balk at the number of new stores Wal-Mart opens every year because the retailer’s capital expenses have grown, on average, 19 percent a year over the last decade, faster than its sales and profit growth.

Last fall, to assuage investors, Wal-Mart said it would reduce the increase in new store space this year by less than 1 percent and choose locations for new stores more carefully. Most people thought that cut would be the last for the year.

But after a closer examination, Wal-Mart chose to chop again. Mr. Schoewe said the company was “committed to providing better returns.”

“The message you are hearing today,” he told shareholders, “is that we have found a real nice balance between appropriate return and the growth of your great company.”

Mr. Schoewe called the reductions a “moderation” and emphasized that Wal-Mart would still add 20 million square feet of new store space this year. “We are committed to growth,” he said.

But the cutback is significant because each Wal-Mart supercenter can book sales of $100 million a year, and the giant stores have propelled much of Wal-Mart’s growth — an increase of more than 13 percent a year, on average, in the last decade.

Wal-Mart remains the dominant retailer in the United States. In 2006, it earned $11.28 billion, with sales of $345 billion.

But sales at stores open at least a year often increased only 1 percent to 2 percent a month throughout the second half of 2006, well below the growth rate at Wal-Mart’s rival, Target, unsettling investors.

Fashionable clothing and home décor did not sell and higher fuel costs harmed Wal-Mart’s working-class customers.

Renovations to older stores have bolstered sales, but Mr. Scott said Wal-Mart must improve its merchandise and store operations — particularly the wait times at cash registers.

The “economic environment is tough for our customers but we just have to work our way through these difficulties,” he said. “We will prevail.”