DMK chief M Karunanidhi and TNCC president K V Thangkabalu signed the agreement, hammered out after hard bargaining by both sides for about a fortnight.
"Following discussions, it has been decided to share 63 seats with Congress," the copy of the agreement released to the media said. Later, Thangkabalu described the DMK-Congress combine as a "winning alliance."
The seat-sharing talks had run into rough weather with DMK refusing to allot 63 seats and Congress dead set on its demand, which had brought the seven-year-old alliance under serious strain.
The stalemate continued till Tuesday when DMK finally relented to Congress's demand for 63 seats.
DMK and Congress had contested the 2004 and 2009 Lok Sabha polls from the same platform besides the 2006 Assembly elections.