Mr Mukherjee, a veteran of the ruling Congress Party, was elected by members of the national and state parliaments.

The position is largely ceremonial but he could help determine who forms the next government after elections in 2014 if there is no clear winner.

Mr Mukherjee's term runs for five years. He replaces Pratibha Patil, who was India's first woman president.

He defeated Purno Sangma, a former speaker of the lower house of parliament who had the backing of the opposition Bharatiya Janata Party.

The BBC's Asia analyst Jill McGivering describes Mr Mukherjee as a grand old man of the Congress Party, a smart operator with political savvy who knows how to forge alliances.

The 2014 elections are not expected to produce a clear result. In that case, the president could play a decisive role.

Correspondents say Mr Mukherjee's victory will come as a big boost to the Congress Party, which has been under pressure over a series of corruption scandals and a slowdown in the Indian economy.

Mr Mukherjee has headed several top government ministries during his career, including the foreign, home, defence and trade ministries.