CAIRO, Sept 29 (Reuters) - Egypt gave the green light on Thursday for Interpol and the European Union to drop charges against Hussein Salem, a businessman ally of deposed president Hosni Mubarak, a senior justice ministry official said.

Salem and his family gave up 75 percent of their wealth in August in a deal that allowed them to return to Egypt without facing prosecution.

Salem, who also holds Spanish citizenship, was arrested under an international warrant in 2011 in Spain, where he fled after the popular uprising that ended Mubarak's 30-year rule.

"The prosecution had sent instructions to take Salem and his family members off airport watchlists on Sept. 27 and asked the Interpol to take him off its Red Notice Wanted list today," justice ministry spokesman Judge Khaled al-Nashar told Reuters.

The International Criminal Police Organization (Interpol) is an intergovernmental agency designed to promote international cooperation in criminal investigations.

Nashar said Egypt also sent notice to Spain, Switzerland, and Hong Kong to take Salem off their watchlists and that of the European Union.

The actions will allow Salem and family members to return to Egypt.

An Egyptian court had sentenced Salem in absentia to seven years in jail and fines totalling more than $4 billion in 2011 after convicting him of money laundering and profiteering.

He later faced graft-related charges associated with gas exports to Israel but was cleared in 2014.

Salem was a major shareholder in East Mediterranean Gas (EMG). Egyptian opposition groups had long complained that EMG was selling gas at preferential prices to Israel and other countries, depriving Egypt of potential revenues.

Egypt's Illicit Gains Authority recovered 5.3 billion Egyptian pounds (US$596.85 million) in the reconciliation deal with the Salem family.

The deal was part of a wider reconciliation effort with wealthy businessmen who fled Egypt after the uprising.

($1 = 8.8799 Egyptian pounds)

(Reporting by Ahmed Aboulenein; Editing by Toni Reinhold) ((ahmed.aboulenein@thomsonreuters.com; +20 2 2394 8097; Reuters Messaging: ahmed.aboulenein.thomsonreuters.com@reuters.net))