(Removes erroneous reference to a sentencing request by the jury in paragraph 3)
* Prosecutors want 2 of 5 convicted men jailed for life
* Request sentences of 15-22 years for three others
* Authorities have not found who had Kremlin critic killed
By Steve Gutterman
MOSCOW, May 27 (Reuters) - Russian prosecutors asked a judge on Tuesday for life sentences for two men convicted of the 2006 murder of journalist Anna Politkovskaya, whose killing deepened Western concerns about the rule of law under President Vladimir Putin.
Life became the maximum sentence for murder in the 1990s when the country imposed a moratorium on the death penalty.
A jury last week convicted five men of a murder that drew international attention to the risks faced by Kremlin critics.
The two facing life in jail are Rustam Makhmoudov, who was convicted of shooting Politikovskaya in her Moscow apartment building, and his uncle Lom-Ali Gaitukayev, found guilty of organising the logistics of the crime, the RIA news agency said.
Prosecutors asked the judge to sentence Makhmoudov's brothers Dzhabrail and Ibragim, who tracked Politkovskaya on the day of the shooting, to 19 and 15 years respectively, and want a 22-year sentence for former policeman Sergei Khadzhikurbanov.
Politkovskaya, who was 48 when she was shot while returning home after shopping for groceries, was best known for her revealing reporting on human rights violations in the North Caucasus province of Chechnya.
Rights activists and relatives of Politkovskaya say those convicted were merely carrying out orders and that justice will not be done until the person behind her contract-style killing is identified and convicted.
Federal investigators said last week that the authorities were doing all they could to identify and arrest that person, but Kremlin critics doubt that will ever happen because of suspicions the trail could lead too close to the government.
Ibragim and Dzhabrail Makhmudov and Khadzhikurbanov were acquitted in 2009, embarrassing prosecutors, but the Supreme Court threw that verdict out and ordered a retrial. Rustam Makhmoudov had eluded arrest until 2011.
It was not immediately clear when the judge would rule on the sentences. (Editing by Louise Ireland)