U.S. commercial property companies are likely to try to go public in greater numbers in coming months as they look to refinance billions of dollars of mortgage debt left over from the boom years of 2005-2007. About $1.24 trillion of U.S. commercial real estate loans — $1.02 trillion held by banks and $221.5 billion bundled into bonds known as commercial mortgage-backed securities — will need to be refinanced over the next four years, according to Deutsche Bank.