BEIJING, March 30-- Sales of homes purchased over two years ago will be exempt from business tax, which is 5.5 percent of the contract price of the house, Chinese authorities said on Monday.

Currently, sales of homes purchased over five years are exempt from the tax.

The new rules are meant to "promote the healthy development of the housing market," Ministry of Finance and the State Administration of Taxation said in a joint statement.

Earlier on Monday, mortgage rules were relaxed, cutting down payment levels for second home buyers to 40 percent from the current 60 to 70 percent.

Down payments for second homes using public housing funds will be cut to 30 percent from the current 60 percent, said a statement jointly published by the central bank, Ministry of Housing and Urban-Rural Development, and China Banking Regulatory Commission.

China's property sector took a downturn in 2014 after years of boom that saw home prices rocket to levels out of the reach of ordinary wage earners. Sales and prices are now falling and investment slowing.

According to an official survey of 70 cities, new home prices dipped in 66 of the cities in February. On a year-on-year basis, the prices dipped in 69 of the cities.

Last week, China's land and housing authorities announced measures to regulate land supply for residential building, asking local governments, in cities or counties with excessive home inventories, to "significantly" reduce the land supply.