Former champions Water and Power Development Authority (WAPDA) said Butt and Asif will feature in their team in the first-class tournament starting in various cities from October 26.
WAPDA chairman Zafar Mahmood confirmed the signing.
"I was told of Butt and Asif's availability so I gave the sports department the go ahead and they have signed them," Mahmood told AFP.
Butt and Asif are undergoing a rehabilitation programme under the Pakistan Cricket Board (PCB) since being relieved of the sanctions imposed on a five-year spot-fixing ban.
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The trio was accused of arranging deliberate no-balls during the Lord's Test against England in return for money in August 2010.
Amir is already playing domestic cricket after being relieved of his five-year ban in January following an amendment in the International Cricket Council's code of conduct which allowed banned players to feature in home matches a few months prior to their ban ends.
Butt and Asif were not given that relaxation.
Mahmood said he was in favour of giving disgraced players a second chance.
Butt said he was keen to play domestic games.
"I have been training for quite some time now and am keen to make a comeback in first-class cricket," Butt told AFP.
PCB last month said it wants Butt and Asif to play club cricket first and then first-class matches.