An overhaul of ING's mortgage rate schedule this morning is the first indication that pricing differentials between investment and owner-occupier mortgages might be set to narrow across the banking industry.ING notified mortgage brokers last night that it was slashing fixed rates on investment loans by up to 36 basis points, while also hiking fixed rates for all owner-occupier loans.The most aggressive repricings, which take effect today, will result in ING's two and three year fixed rates for investment borrowers being cut by 18 and 36 basis points respectively to 4.19 per cent. These fixed products are now cheaper than ING's variable investment rate priced at 4.24 per cent.However, owner-occupiers are facing across-the-board hikes on standard and bundled fixed rates.The standard rate on owner-occupier loans fixed for one year will climb 17 basis points to 3.85 per cent.Standard pricing on four year fixed rate mortgages for owner-occupiers will rise 26 basis points to 4.19 per cent.Borrowers who also hold an Orange Advantage account will be eligible discounts of up to 10 basis points on the standard rates.While time will tell whether other lenders will follow the ING moves, they also indicate that the bank has received the green light from APRA to remove the 10 per cent monthly growth cap on investment lending.A string of banks including Macquarie, People's Choice CU and HSBC Australia were liberated from the growth cap in July and August.