Capmark's attorney, Rob Robertson, could not be reached for comment Thursday.
The First National Center will lose one of its biggest tenants, Devon Energy Corp., next summer when the energy company's lease expires.
Meanwhile, Yashouafar faces other legal problems. He pleaded guilty in July to an embezzlement charge after being accused of diverting insurance proceeds after a fire at a Las Vegas condominium development. He must pay $1 million in restitution to Paradise Spa condominium residents before his sentencing in November, Nevada court records show.
Earlier this month, The Oklahoman reported Yashouafar was under federal investigation for submitting questionable reimbursement forms to Oklahoma City officials for asbestos removal.