Washington, Jun 28 (IANS/EFE): The number of chimpanzees used in biomedical research in the US will be reduced sharply because technological advances have made their use unnecessary, the National Institutes of Health, or NIH, said.

"Americans have benefited greatly from the chimpanzees' service to biomedical research, but new scientific methods and technologies have rendered their use in research largely unnecessary," NIH director Francis Collins said in a statement.

The decision opens the way for 310 of the 360 chimps owned by the NIH to enter retirement at federal refuges over the next few years, with only 50 chimps being kept for future research.

"The chimpanzees designated for retirement could eventually join more than 150 other chimpanzees already in the Federal Sanctuary System. The Federal Sanctuary System was established in 2002 by the Chimpanzee Health Improvement, Maintenance and Protection (CHIMP) Act and Chimp Haven operates the Federal Sanctuary System, which is overseen by NIH," the agency said.

The 50 chimpanzees retained for future biomedical research will not be allowed to breed and will only be available for use in projects that meet strict criteria, the NIH said.

"Their likeness to humans has made them uniquely valuable for certain types of research, but also demands greater justification for their use. After extensive consideration with the expert guidance of many, I am confident that greatly reducing their use in biomedical research is scientifically sound and the right thing to do," Collins said.

The NIH, which is an agency of the US Department of Health and Human Services, has 27 institutes and centers.