NEW DELHI: Indian Prime Minister Manmohan Singh was sworn in for a second term Friday, even as talks broke down between his party and a key coalition partner.

President Pratibha Patil, dressed in an elaborate white green and gold sari, administered the oath of office to Singh and his core Cabinet in a formal ceremony in New Delhi's imposing red-stone presidential palace.

Only 19 senior ministers were sworn in with several more expected to take the oath next week in a second ceremony, according to a statement from Singh's office.

The delay was apparently to allow the Congress party time to complete coalition negotiations with some of its allies. The DMK, a regional party from southern India, walked out after Congress failed to agree to their demands, said T.R. Baalu, a senior party member. Party leader M. Karunanidhi and his large entourage packed their bags and flew out of New Delhi early Friday.

Singh, 76, wearing his trademark blue turban, swore to "preserve, protect and defend the Constitution," and to "devote myself to the service and well-being of the people of Republic of India."

A second term is seen as a victory for Singh, a famously stiff man who describes himself as an accidental politician.

Singh, a mild-mannered former economist with a reputation for honesty, was thrust into the position of prime minister in 2004 when the Italian-born Congress party chief Sonia Gandhi declined the position and picked him.

He has since had to contend with charges of being Gandhi's puppet and doubts over his health, following a heart surgery earlier this year.

The Cabinet portfolios of the 19 ministers were not announced, but they included several senior members of the previous administration, including Foreign Minister Pranab Mukherjee, Defense Minister A.K. Antony and Home Minister Palaniappan Chidambaram.

Singh's nascent government was already deeply mired in the intricacies of Indian coalition politics.

The DMK had campaigned together with Congress, but with the two parties making substantial gains at the polls, both were trying to get a better deal.

Congress still has enough support to govern even without the DMK and the party was widely expected to eventually join the government, with talks set to continue after the ceremony while both parties reassessed their stands.

"We are not at all worried. We are friends," Baalu said.

Congress — which has been trying to bolster its image as a clean party under Singh_ was also reportedly unhappy with Karunanidhi's picks to be ministers in the new Cabinet, which included two senior party leaders tainted by corruption charges and also Karunanidhi's son, daughter and a nephew.