Dolly, the cloned sheep, is pregnant, a newspaper reported Sunday.

Scientists at Edinburgh's Roslin Institute, who made history when they cloned Dolly from the cell of another sheep's udder last year, will announce the happy event this week to coincide with publication of the institute's financial results, the Sunday Times of London said.There was no one immediately available to comment at the Roslin Institute.

Healthy lambs would mean that the cloning process had produced a fully healthy, fertile sheep, which would be valuable knowledge for PPL Therapeutics, the Scottish biotechnology company formed to market the center's work.

The birth of a healthy lamb would also help counter fears that Dolly may be prone to premature aging and other age-related disorders as a result of being cloned from a 6-year-old adult.

Dolly, a Finn Dorset sheep who is now nearly 2 years old, is the first mammal cloned from the cell of another adult mammal.

In January, scientists at the institute announced that Dolly had been mated. The Sunday Times said she has been in partial quarantine for the past month to minimize the risk of miscarriage. Extensive prenatal testing had suggested that both she and her offspring are healthy, the newspaper reported.

Scientists say any offspring will not be clones and will be genetically different from their mother.

The institute already has proven that cloned animals can reproduce.