US STOCKS-Wall St lower on China concerns; Greece watched
* China slowdown fears drags commodities towards 2015 lows
* Falling U.S Treasury yields weigh on financials
* S&P 500 briefly fell below 200-day moving average
* AMD revenue warning weigh on semiconductor index
* Indexes down: Dow 0.5 pct, S&P 0.4 pct, Nasdaq 1 pct (Adds details, updates prices)
By Tanya Agrawal
July 7 (Reuters) - U.S. stocks were lower in afternoon trading as concerns of a slowdown in China weighed on commodity prices and investors fretted over aid talks for Greece as it runs out of cash.
The market made up some ground after the S&P 500 index briefly fell below a key technical mark and moved into negative territory for the year.
The Dow Jones Industrial Average is in negative territory for the year, while the Nasdaq fell to a two-month low. Continuación...