While Muraleedharan said his party would actively work for UDF's victory, Chennitala said he was happy that all Congressmen were reuniting under the leadership of Sonia Gandhi.
The NCP's flag was handed over by Praful Patel to K Muraleedharan, DIC-K president, signifying the merger.
Both parties refusing to yield on the key issue of number of DIC-K candidates contesting on Congress symbol.
Expressing confidence, he said the party would emerge victorious.
The NCP national leadership would take an appropriate decision on NCP state leadership posts after the merger.
Ruling out merger with any political party currently, Democratic Indira Congress (K) president K Muraleedharan Tuesday clarified that the party would contest all the 140 seats on its own, in the forthcoming Assembly elections.
DIC(K) factor to delay UDF seat-sharing
Democratic Indira Congress (K) state vice president and former Kerala minister P Sankaran on Wednesday announced that he was quitting the party and returning to the Congress.
The LDF unanimously decided not to have NCP in the front considering the "changed political climate" in that party after its merger with DIC-K on November 12, front convener Vaikom Viswan told reporters in Thiruvananthapuram.
The split in the Congress in the state caused by K Karunakaran has also helped LDF maintain its winning spree.