UPDATE 3-Algeria's Bouteflika to resign before mandate ends April 28 -state news agency

Algerian President Abdelaziz Bouteflika will resign before his mandate ends on April 28, state news agency APS said on Monday, after more than a month of mass protests and army pressure seeking an end to his 20-year rule. APS said Bouteflika, who is 82 and in poor health, would take important decisions to ensure "continuity of the state's institutions" before stepping down. It did not spell out a date for Bouteflika's departure.

Under the constitution of the oil producing North African state, Abdelkader Bensalah, chairman of the upper house of parliament, would take over as caretaker president for 90 days until elections are held. In a move to defuse the unrest, Bouteflika said on March 11 he was dropping plans to run for a fifth term.

But he had stopped short of leaving immediately in favour of waiting for a national conference on reforms to address discontent over corruption, nepotism, mismanagement and the prolonged grip on power of elderly veterans of the 1954-62 war of independence against France. Bouteflika's hesitation further enraged protesters, spurring the powerful army chief of staff to step in by proposing last week to implement a provision of Algeria's constitution that calls for a constitutional council to determine whether Bouteflika was still fit to govern or allow him to resign. (Reporting by Lamine Chikhi and Hamid Ould Ahmed with additional reporting by Aziz El Yaakoubi Writing by Ulf Laessing Editing by Mark Heinrich)