The marathon meeting, spread over two sessions and kept under wraps, came a day after top leaders of socialist-leaning parties attended SP's silver jubilee meet here -- a move seen as an attempt by Mulayam to forge an alliance ahead of the assembly polls hardly a few months away.
There was no official word from either side as to what transpired at the meeting.
State SP President Shivpal Yadav said he would tell the media when such a development took place.
"When it materialises, I will tell you," Shivpal told media persons.
This is for the second time in six days that Kishor met Mulayam, who is trying to cobble together an alliance of like-minded parties.
The first meeting took place at Mulayam's Delhi residence on November 1.
Samajwadi Party, which was initially part of Bihar's grand alliance, had walked out of it after it was offered only a handful of seats to contest the assembly elections there.
The grand alliance of Janata Dal-United, Rashtriya Janata Dal and the Congress had, however, scripted a glorious electoral victory, defeating the BJP-led National Democratic Alliance.
The ruling SP is yet to open its cards though its main aim in the polls is to prevent split of Muslim votes for which it is looking for an alliance with secular parties.
The Congress, on its part, has not closed its doors for any possible grand alliance for the 2017 assembly polls. But, Uttar Pradesh Congress Committee chief Raj Babbar has said that no initiative has been taken for an alliance either by his party or by any other political parties in the state.
"No initiative for an alliance, either by us or by any other party in the coming polls has been taken, but Congress has not closed its doors for any such possibility which could benefit people of the state," he had said on Friday.
The UPCC chief, however, stressed his party "will not enter into an alliance or grand alliance only for numbers, as numbers were not important in UP polls."
At SP's anniversary bash yesterday, leaders of erstwhile 'Janata Parivar' underscored the need for unity to prevent the "communal" BJP from coming to power and spoke about the need for forging a coalition.
RJD supremo Lalu Prasad declared his party will not contest the UP elections to prevent a split of secular votes.
JD-U's Sharad Yadav hinted at his party's readiness to form a coalition of socialist parties, while Rashtriya Lok Dal chief Ajit Singh, whose party wields influence in western UP, highlighted the need for unity.
Former Prime Minister H D Deve Gowda, whose Janata Dal-Secular hardly has any stake in UP or the Hindi heartland, urged the 'Janata Parivar' leaders to "come together and unite" against the "communal" forces.
"Senior leaders Mulayam Singh Yadav, Lalu Prasad, Sharad Yadav...should come together in the fight against communal forces," Deve Gowda had said.
Six offshoots of 'Janata Parivar' had merged together last year ahead of the assembly elections in Bihar to form a new party to take on a resurgent BJP. The merger took place almost two decades after the then Janata Dal disintegrated in the 90s.