Presidential spokesman Farhatullah Babar said Shahabuddin, considered a Pakistan People's Party loyalist, will file nomination papers in parliament later today.
The PPP's coalition has a majority in parliament and barring last minute surprises is expected to be able to vote him into office in a session scheduled for Friday.
Outgoing prime minister Yousuf Gilani was dismissed by the Supreme Court on Tuesday for contempt of court.
The decision to nominate a replacement quickly means that the government is not defying the court order as some had predicted it might.
General elections must be held before March 2013, so the new premier will not have long in office.