Retrial of Egypt's Mubarak and sons set for April 13 By Marwa Awad CAIRO (Reuters) - An Egyptian court set the date on Sunday for a retrial of ousted leader Hosni Mubarak, his sons and top aides, ordering the politically fraught hearings over the killing of protesters to start just nine days before parliamentary elections next month. Mubarak, who was toppled in a popular revolt in 2011, was jailed for life for ordering the killing of demonstrators, but was later granted a retrial by a Cairo court. The 84-year-old is now being treated in a military hospital. His sons and other figures have also faced charges of corruption and squandering public funds, due to be reheard. The retrial could raise tensions at a time of political and economic turmoil in Egypt, which has seen waves of street unrest throughout the two years since Mubarak stepped down. New Islamist President Mohamed Mursi accuses his supporters of fomenting some of the unrest. The hearings are likely to overlap with the parliamentary vote, which begins on April 22 and will be held in four stages until late June. Many opposition parties say they will boycott the elections called by Mursi. Mubarak was ousted in February 2011 after 30 years in power and was the first Arab ruler to be brought to court by his own people. Businessman Hussein Salem, convicted in absentia in 2011, sentenced to seven years in jail and fined more than $4 billion for money laundering and profiteering, is also due to be retried for selling cheap gas to Israel and squandering public funds. Editing by David Stamp and Peter Graff