Toys R Us Inc., which operates 875 stores in the U.S., is preparing to refinance a big chunk of those stores in the CMBS market looking to raise up to $512 million. Such a refinancing would help pave the way for the toy retailer to obtain additional mezzanine financing of $88 million. The retailer and one of its property operating subsidiaries have begun negotiating definitive documentation for a new mezz facility.