The companies, KHOC LLC, BJK LLC and Mantua Land Co, filed for protection in Fort Lauderdale, Fla. Kosar filed for personal bankruptcy court protection Friday, The Miami Herald reported Tuesday.
Kosar's attorney Julianne Frank said she would try to consolidate the bankruptcy cases. Kosar's holdings in the businesses "will put us in a position to consummate a successful restructuring," she said.
KHOC manages Kosar's minority interest in the Florida Panthers, a hockey team which may soon be sold for $240 million, the newspaper said.
The other two companies, based out of Kosar's home, have invested in properties in Florida and Ohio.
Kosar's football career took him from the University of Miami to the Cleveland Browns. He retired from football in 1996, after spending time with the Dallas Cowboys and the Miami Dolphins.