Mr. Karzai, who is beginning his second term, is due to present his selections for the 25 posts on Saturday. The list is widely seen as a test of President Karzai's commitment to reform, after being re-elected in a disputed presidential vote in August.
Western nations have been pressing Mr. Karzai to rid his government of corruption and have threatened to hold back troops and aid unless he does.
The nominees expected to retain their positions include the ministers of defense, interior, finance, foreign affairs, health and agriculture -- all well regarded by Mr. Karzai's Western allies.
But Afghan officials say President Karzai also plans to keep energy minister Ismail Khan, who has been accused by Human Rights Watch of committing war crimes.
In a separate development, Afghan officials say three civilians were killed during a NATO air strike against suspected militants in the country's south.
Officials say the civilians were traveling in a minibus late Thursday in the Shah Wali Kot district of Kandahar province, when they were attacked by helicopter gunships.
NATO says the attack targeted militants planting explosive devices along the road. The alliance says it is investigating the reported casualties.
Some information for this report was provided by AFP, AP and Reuters.