A Texas woman who said she paid $50,000 to a Northern California biotech company has received an 8-week-old clone of her dead cat, Nicky, in the first known sale of a cloned pet.

Genetic Savings & Clone Inc., based in Sausalito, handed over Little Nicky, a Maine coon cat, earlier this month at a company holiday party in San Francisco.

"He is identical. I have not been able to see one difference," said the woman, who asked to be identified only by her first name, Julie.

The company has been working for more than four years on cloning cats. The founder of the company, Arizona billionaire John Sperling, funded the research at Texas A&M University that led to the cloning of the first cat in 2001, CC, or Carbon Copy.

The company is employing a technology known as chromatin transfer that is currently being used for cloning cattle.

Company spokesman Ben Carlson said four other people have cats on order, at $50,000 each. He said all the clones are expected to be ready by spring.

The announcement of Little Nicky sparked criticism from some animal protection groups, who saw the event as opening the door to a new realm of problems.

"There are millions of cats being killed in shelters every year," said Michael Mountain, president of Best Friends Animal Society. "There is no shortage of cats, so why do they have to do this?"

He described the cloning of animals -- still a complex and tricky procedure that can result in deformities and genetic abnormalities -- as an inhumane game of trial and error.

But Lou Hawthorne, chief executive of Genetic Savings & Clone, said there is no denying the intense desire of some pet owners to bring back their deceased companions.

"We're not curing cancer, but we believe we are adding to the sum of joy in the world," Hawthorne said.

Michael Grodin, a psychiatrist and director of medical ethics at the Boston University schools of medicine and public health, said he saw no ethical problem with the procedure.

"Many people have a better and stronger and more humane relationship with their pets than they do with other human beings," he said. "Who am I to say that somebody shouldn't clone their cat?"

The original Nicky died in September 2003 at age 17.

Julie, who did not wish to be identified further, holds 8-week-old Little Nicky, a clone of a cat that died in 2003 at age 17.