Former prime minister Nawaz Sharif late Saturday declared victory for his centre-right opposition Pakistan Muslim League-N (PML-N) party and invited other parties to work with him.
"We should thank Allah that he has given PML-N another chance to serve you and Pakistan," he said in a speech to jubilant supporters at his party headquarters in Lahore.
The crowd shouted "prime minister Nawaz Sharif" and chanted "lion", Sharif's nickname, as they danced and waved flags and toy tigers, the party's election symbol, said an AFP reporter.
A PML-N victory will hand hand Sharif a historic third term as prime minister.
According to the unofficial, partial results it appeared that no single party would win a simple majority of 172 seats in the national assembly, raising the prospect of protracted talks to form a coalition government.
"Whatever promises we made with our youth, I assure you that we fulfil each of them. Results are still coming but there is a confirmation that PML-N will emerge as the largest party," Sharif said, surrounded by his close family.
"I appeal for all parties to come to the table and sit with me and solve the country's problems," Sharif said.
"I'm doing this only because of you. If it had been only myself, I would not talk to them but it's for you and for the survival of your future generations," he added.
Sharif served as prime minister from 1990-93, when he was sacked for corruption, and from 1997-99, when he was deposed by the military, although his family say he is a changed man who will this time govern more successfully.