"Malik has been chosen as the next captain after the refusal of Younis Khan to lead the side," a reliable source in the board told Reuters.
"You can expect an official announcement on Malik later this week," he said.
Malik has been chosen after senior batsman, Younis Khan, who was offered the captaincy by the board chairman last week, turned it down, insisting he was more comfortable playing as a senior player in the side.
Pakistan started their search for a new captain after Inzamam stepped down as captain and retired from one-day internationals following the team's poor performance in the World Cup.
Pakistan were eliminated from the tournament's first round after losing to debutants Ireland on March 17. They had earlier lost to hosts West Indies.
A day later their coach, Bob Woolmer, died in Kingston, Jamaica and police are now investigating his death as a murder.
"Malik has been picked after careful consideration and taking into account his own performances and also the future of Pakistan cricket," the board source said.
The Pakistan board had many potential candidates for the captaincy after the refusal of Younis with senior player Mohammad Yousuf and all-rounders, Shahid Afridi and Abdul Razzaq all offering to take up the captaincy.
The Pakistan captaincy has never been an easy job and Inzamam as captain brought a certain amount of stability to the side since being made skipper in Nov 2003.
Malik, 25, who has played in 18 Tests and 137 one-day internationals, declined to comment on the issue.
"I don't want to say anything because no one has spoken to me about it as yet. When it happens fine," he told.
A senior board official, however, confirmed that the new captain would be named in the next three to four days.
"I can't say who is under consideration but some candidates have been discussed," Saleem Altaf said.
He said that in all probability the board would stick to its policy of appointing the captain for both test and one-day squads.
But sources said it had been decided Malik would be appointed on a series-to-series basis with his first assignment not until the ICC Twenty20 World Cup in September.
The PCB is also due to appoint a coach in place of Woolmer.