After withdrawing support to the UPA government over the Sri Lankan Tamil issue, DMK's five representatives resigned from the Union Council of Ministers which were accepted by Prime Minister Manmohan Singh late on Wednesday night.
Singh, who forwarded the resignation letters to President Pranab Mukherjee, also allocated the charge of chemicals and fertilizers ministry to Srikant Jena who is minister of state in the same ministry.
The portfolio was till now held by DMK's MK Alagiri who submitted his resignation on Wednesday, as was done by his other four colleagues - D Napoleon, SS Palanimanickam, S Gandhiselvan and S Jagatrakshakan.
Alagiri and D Napoleon did not accompany the other three DMK ministers SS Palanimanickam, S Gandhiselvan and S Jagatrakshakan to submit their resignations to the Prime Minister at around noon at his Parliament House office and went separately an hour later to submit their resignations.
There was speculation that DMK chief M Karunanidhi's son Alagiri was unhappy for not being kept in the loop over the party's decision to pull out of UPA.
While Alagiri was a cabinet rank minister, Napoleon, Palani Manickam, Jagatrakshakan and Gandhiselvan were ministers of state.
DMK, which ended its nine-year-old alliance with UPA yesterday, has 18 members in the Lok Sabha and six in the Rajya Sabha.
The party ruled out supporting UPA from outside or joining the BJP-led NDA.
DMK parliamentary party leader TR Baalu told reporters that "as per the decision taken by Kalaignar Karunanidhi, we have handed over the resignation letter to the Prime Minister."
Baalu, who accompanied the ministers while submitting their resignations to the Prime Minister, said his party will not join BJP-led NDA.
Karunanidhi also ruled out outside support to UPA government.
DMK, which was the second biggest constituent of UPA, quit the ruling alliance in protest against the government not taking up its concerns in the proposed UN resolution against Sri Lanka on alleged human rights violations of Tamils there.