PARIS (AFP) - France inaugurated a specialised agency for approving research on embryonic stem cells and vetting organ donations and other bioethics issues.

The creation of the Biomedicine Agency follows up on a new law, approved by parliament last August and due to take effect this month.

Under it, French health scientists will be permitted to draw on the country's stock of tens of thousands of surplus embryos in order to create lines of stem cells.

These embryos were created years ago through in-vitro fertilisation (IVF) to help infertile couples, but are no longer wanted and remain in freezers in fertility clinics.

Stem cells are immature cells that are like blank slates. In this early state, they have yet to differentiate into the specific cells that make up the body's tissues.

The goal among scientists is to harvest these cells and coax them into growing into fresh, replacement tissue which can then be transplanted into the body to reverse brain, nerve, muscle and organ damage.

The most versatile stem cells come from embryos that are a few days old. These cells can differentiate into any part of the body.

But embryonic cells have also ignited fierce objections from conservative religious groups who say that the tissue has the same moral value as a baby.

The new law will enable French researchers to grow lines of stemcells provided tightly-controlled therapeutic and ethical criteria are met and the couple who created the embryo give their consent.

However, the law will only last five years -- a duration scorned by many researchers as a poor compromise that will cause France to lag behind its competitors in this new area of medicine.

For the past few months, researchers have been allowed for the first time to import stemcell lines as a stopgap.

The Agency for Biomedicine will also be in charge of authorising screening of IVF embryos that are selected to be free of inherited disease and which are destined, after birth, for providing bone marrow or other replaceable tissue for sick siblings.