Congress and Trinamool Congress reached a seat-sharing accord for Lok Sabha polls in West Bengal on Wednesday night to put up a joint fight against the state's ruling Left Front, a day after the Mamata Banerjee-led party had served a 48-hour ultimatum for the agreement to be clinched.

Capping weeks of hard bargaining, Congress finally accepted Trinamool Congress' seat-sharing formula and will contest 14 of the 42 seats while Trinamool Congress would be in fray in 28.

"The alliance has been finalized. Congress will contest in 14 seats," senior Congress leader Kesava Rao told PTI in New Delhi [Images].

He said a formal announcement about the seat-sharing agreement would take place any moment.

Sukhendu Sekhar Roy, an emissary of WBPCC president and External Affairs Minister Pranab Mukherjee [Images], met TC chief Mamata Banerjee at her south Kolkata office to convey Congress' decision to accept her party's seat-sharing formula.

Roy said he met Banerjee on behalf of Mukherjee to convey the PCC chief's best wishes to her "to give leadership to the important political fight (Lok Sabha poll) and beyond."

Banerjee had on Tuesday given the ultimatum to Congress to communicate its decision on seat-sharing accord proposed by TC between the two parties. She said TC will contest 28 seats leaving 14 to Congress.

Congress had reservations about TC's seat-sharing formula on the ground that some of the seats offered by Mamata Banerjee-led party were "difficult to win" being in strongholds of CPI(M).

The seat-sharing deal of 28 seats to be contested by Trinamool Congress and 14 by Congress was first agreed to at a meeting between Mukherjee Rao, AICC in-charge of the state, on March one.

While issuing the ultimatum, Banerjee had said, "We have been waiting for ten days and we cannot wait forever. There is a limit. If Congress is sincerely interested in alliance to defeat the CPI-M, they must inform us within a day or two."

She had also said that TC was "ready for any situation. If there is an alliance it is okay otherwise we will fight on our own".

At the March one meeting, Mukherjee had asked her to give five seats to Congress in South Bengal and nine in North Bengal, the TC supremo had said adding Congress was given seats like Bankura, Arambagh, Jhargram, Bolpur, Purulia, Burdwan-Durgapur.

"These are all winnable seats. Had we contested these seats, we would have done well but in the interest of the alliance, we left the seats for Congress," she said.

She also said that in the 2004 Lok Sabha poll, when the performance of Trinamool, then an NDA ally, was its worst, Congress had won six seats and came second in two.