NEW YORK (TheStreet) -- Home prices are still rising but at a slower pace, largely due to the growing supply in the market. Prices remained flat in September from the previous month but were up 4.9% from a year earlier, according to Tuesday's S&P/Case-Shiller Home Price index, which measures prices of 20 metropolitan cities. Must Read: 10 Stocks Billionaire John Paulson Loves in 2014 "A large part of the slowdown in prices comes from increasing supply," David Blitzer, chairman of the index committee at S&P Dow Jones Indices, told TheStreet.