June 21/Seattle/Wall Street Journal -- Starbucks Corp. plans to raise prices by an average of 1% on some of its beverages in the U.S. It would mark the first price change in 18 to 24 months for some markets, the company said.

Increasing rent, labor and non-coffee commodity costs as well as competitive dynamics are the reasons behind the new pricing, Starbucks spokesman Jim Olson said. Coffee costs have been on the decline and for that reason -- and to keep up with rivals -- Starbucks in May reduced the price of its packaged coffee sold in U.S. retail outlets by an average of 10%.

Less than one-third of beverages will be affected by the price increases. In most stores, the price of a Grande or Venti brewed coffee, as well as Frappuccino and Refreshers, will remain the same.

In markets where the price of a Tall brewed coffee is changing, the biggest rise would be 10 cents, Olson said, adding that he cannot share specific price increases of specific drinks in different markets for competitive reasons.

At Starbucks retail stores, coffee represents less than 10% of stores' operating costs, he said.