The worldwide coffee retailer said Tuesday it is moving forward with long-promised plans to make the milk and other dairy products it serves in its U.S. coffee houses free of a controversial artificial growth hormone used to increase milk production.

    A conversion is initially aimed at all 5,500 U.S. company-owned stores, but Seattle-based Starbucks is also exploring such a move with more than 3,000 licensed locations, a company spokesman said.

    "This is something that our customers have requested," Starbucks spokesman Brandon Borrman told Reuters. "It is just making sure our suppliers can supply the amount of milk we need."

    The move comes after Starbucks was singled out in a campaign by consumer groups critical of the use of an artificial hormone known as rBGH, which is given as a supplement to dairy cows to increase milk production.

    "We are actively engaged with all our dairy suppliers to explore converting our core dairy products to be rBGH-free in our U.S. company-owned stores," Borrman said. "It is something we're aiming for."

    Borrman said the company this month had already boosted the percentage of its supply that is free of the hormone to 37 percent from 27 percent at the end of 2006. It has not yet said when all of its stores will have milk free of the hormone.

    Borrman said so far the company has been able to provide rBGH-free dairy products in Alaska, Idaho, Montana, New England, New Mexico, Northern California, Oregon and Washington.

    Patty Lovera, assistant director for Food and Water Watch, which challenged Starbucks to make a switch, said it was "encouraging" to hear of the company's efforts.

    "We want to see them actually get it done," Lovera said.

    Ronnie Cummins, national director of the Organic Consumers Association and one of the first groups to pressure Starbucks on this issue years ago, said he was pleased to hear the company was increasing its use of rGBH-free milk.

    Still, he said he was puzzled that the company hadn't used its clout to pressure suppliers more quickly.

    "This is a step in the right direction, but they're moving rather slowly," he said.

    Starbucks started talking about offering milk free of artificial hormones as early as 2000, said Starbucks spokeswoman Sanja Gould.

    But after initially pledging to make the change rather quickly, the company was forced to scale back its plans after it learned its suppliers could not provide enough milk free of rBGH to meet the needs of all its stores.

    Gould said one problem was that, at the time, the only way to ensure that milk was free of rBGH was to buy organic milk, and there wasn't enough organic milk being produced. But now, she said, suppliers are increasingly offering milk that is free of the hormone but is not organic.

    She said the company is continuing to look at offering fully organic milk, but that there still isn't enough supply. Right now, it is offered as an option, for an extra fee, at some stores.

    The dairy products involved include fluid milk, half-and-half, whipping cream and eggnog. Borrman said there is no similar move for overseas locations because the supplement is not allowed in "most other nations."

    Critics say that rBGH given to dairy cows increases the level of another growth hormone in both cows and humans known as IGF-1, and that elevated levels of IGF-1 has been associated with increased cancer rates. Critics also say growth hormone supplements are harmful to the dairy cows.

    Proponents of the hormone supplement say there are no health concerns for humans or the cows, and milk products from cows given the supplement are no different from milk from cows that don't receive the supplement.

    Earlier this month, Starbucks said it was making sure all of its pastries and other foods sold at half of its U.S. outlets would be free of artery-clogging trans-fats.

    (Agencies)