Westpac is the latest mortgage lender to loosen restrictions on property investors.According to a Fairfax Media report, Westpac has written to brokers telling them the maximum loan-to-valuation ratio for loans to property investors has gone up from 80 per cent to 90 per cent.Comparison site Mozo has reported that with growth in lending to residential property investors within the ten per cent limit set by regulators, a number of lenders have been cutting rate premiums and other restrictions on investors.Mozo said AMP, Aussie, Defence Bank, Suncorp, ME and Newcastle had all made changes to make it easier for investors to borrow.Australian Prudential Regulation Authority figures show that Westpac's overall home lending grew by 7.2 per cent over the 12 months to March but its lending to residential property investors fell eight per cent.