Indian voters handed the ruling Congress party a powerful mandate to modernise the country's economy in pursuit of prosperity and stability in an election result expected to bolster confidence in Indian markets on Monday.
The Congress party defied expectations as it claimed an overwhelming victory in India's parliamentary elections in May 2009.
Voters backed the secular leadership and the continued premiership of Manmohan Singh.
Party workers celebrated the Congress' victory in camps across the country.
Manmohan Singh became the first prime minister since Jawaharlal Nehru to be returned to office after completing a full term.
The win also underscored the appeal of the powerful Nehru-Gandhi ruling dynasty, led by Sonia Gandhi and her son Rahul.
The UPA had won 262 of the 543 parliamentary seats, confounding predictions of an inconclusive poll producing a weak coalition.
The party's success meant that it had the upper hand in post-poll bargaining to reach a majority of 272 seats.
L K Advani offered his resignation after his National Democratic Alliance trailed the Congress-led grouping with 160 seats.
One of the most surprising outcome of these elections was a severe decimation of the Left parties, both in West Bengal and Kerala.
Mayawati, the leader of the Bahujan Samaj party, failed to materialise as a key national power-broker.
