* Says potentially mitigating circumstances overlooked
* Two women from Pussy Riot serving two-year sentences
* Due for release in March and could benefit from amnesty
By Steve Gutterman
MOSCOW, Dec 12 (Reuters) - The Russian Supreme Court has ordered a review of the case against two women from punk band Pussy Riot, saying lower courts failed to provide full evidence of their guilt and overlooked mitigating factors in sentencing them to two years in prison.
The ruling could potentially lead to shorter sentences for Nadezhda Tolokonnikova and Maria Alyokhina or even to a reversal of their convictions, although the latter is far less likely.
Tolokonnikova, 24, and Alyokhina, 25, were convicted of hooliganism motivated by religious hatred for performing a crude "punk prayer" in a Russian Orthodox cathedral in protest at President Vladimir Putin and his ties with the church.
Both are due for release in early March and could be freed earlier under an amnesty parliament plans to approve this month, but a major change in the verdict or sentence would embarrass Putin and his government.
It would reinforce critics' accusations that the women were railroaded into prison as part of a clampdown on dissent.
Putin has rejected criticism from Western governments that have called the sentences disproportionate, suggesting last year that the women had threatened the "moral foundations" of Russia and got what they deserved.
The Supreme Court, in an order posted on its website on Thursday and dated Dec. 10, said the trial court did not provide evidence of a portion of the verdict that says they were motivated by "hatred of a certain social group".
It also said potentially mitigating circumstances were not taken into account when they were sentenced, including their youth, the fact that both have young children, and calls for leniency from people considered victims in the case.
An appeals court upheld the verdict and sentences against Tolokonnikova and Alyokhina in October 2012 and suspended the sentence of a third woman convicted at the same trial, Yekaterina Samutsevich.
Tolokonnikova and Alyokhina could be freed before their sentences expire in March because Putin has submitted an amnesty proposal to parliament that would release many inmates convicted of hooliganism and also many who are mothers of young children.
(Editing by Alison Williams)