Banks in Shanghai are split on the second home mortgage interest rate as regulators didn't specify it.

Some lenders, including the Bank of China, said they don't offer any discounts on the rate for second home loans. But the Bank of Shanghai said it offers up to 30 percent discount on the rate to eligible clients. The Bank of Communications said it offers up to 29 percent discount to clients with a good credit history.

Industry watchers said regulators are to issue guidance on individual mortgages soon to trim risks.

In September 2007, authorities asked banks to require at least a 40 percent down payment and to charge an interest rate at least 10 percent higher than the benchmark rates on second home loans to curb the then red-hot real estate market.

In December 2007, the regulators issued a follow-up notice which clarified that banks should use family, including the loan applicant's spouse or child, as the criteria to determine second homes. But many banks bypassed the requirement in 2008 and early 2009 to boost business when the property market lost steam.