A headdress said to have belonged to the last Aztec emperor could return to Mexico temporarily from Austria.
The headdress is believed to be a gift from Montezuma to 16th Century Spanish conquistador Hernan Cortes.
It is made of quetzal and other feathers mounted on a base of gold studded with precious stones.
Mexico usually sees pre-Conquest relics as national property, which must stay in the country.
But the headdress could be returned on an extended loan from a museum in Vienna where it is currently on display, after a change in the rules.
However, the senate has agreed to accept a temporary loan, while acknowledging Austria's ownership rights.
It is thought Cortes sent it to the Spanish king in Europe. It is unclear how it ended up in Austria, although the king was a member of the Austrian Hapsburg family.
Details of the loan still need to worked out. Mexico has tried to get the headdress returned for many years.
