McDonald's Corp. (MCD) plans to make specialty coffee drinks available in all of its U.S. restaurants by the end of 2008, according to a published report Monday.

The world's largest fast-food chain has been talking openly for nearly a year about plans to add such drinks as lattes and cappuccinos following its success with premium coffee, introduced in 2006.

Crain's Chicago Business, citing planning documents, reported that the rollout of the new coffee drinks will occur in 1,500 restaurants by the end of this year and in the rest of U.S. restaurants by the end of 2008. It said McDonald's predicts the new drinks will add more than $1 billion a year to sales.

McDonald's reiterated Monday that it is testing specialty coffee, among other products, but said no final decisions have been made on when they might be introduced widely.

"To speculate beyond this, or comment on rumors, would be irresponsible and inaccurate," spokeswoman Danya Proud said in a statement.