The deal was struck after AJSU Chief Sudesh Mahto met BJP President Amit Shah and both sides sealed the tie-up following a recommendation of BJP's state unit, BJP General Secretary Bhupinder Yadav, who is also in charge of the party's Jharkhand affairs, said.
"BJP has decided to tie up with like-minded parties in Jharkhand and will contest the upcoming Assembly polls with AJSU. Talks between AJSU and the state leadership were on and they have been successfully concluded," he told reporters.
Among the Assembly seats that BJP has given its new ally are Jugsalai, Chandankyari, Silli, Ramgarh and Lohardaga, currently represented by AJSU, along with the Barkagaon seat.
Yadav said two other seats will be decided by AJSU and its state leadership.
"Our aim is to form a government in Jharkhand with a two- thirds majority that could provide a stable regime to help improve law and order and take the state forward on a speedy path of progress," he said.