US STOCKS-Shares fall amid talks over Greece, fiscal cliff
* Euro zone finance ministers begin third attempt at Greek deal
* Investors to take profits after last week's strong finish
* Qatar cashes in its warrants in Barclays, causing shares to dip
* Knight Capital in talks for unit sale; shares jump
* Indexes: Dow off 0.5 pct; S&P off 0.4 pct; Nasdaq flat
By Angela Moon
NEW YORK, Nov 26 (Reuters) - U.S. stocks fell on Monday as investors returned to the market after a holiday, focused on euro zone talks to release aid to Greece and negotiations in Washington to avoid the U.S. "fiscal cliff."
Investors were also ready to book profits after major indexes ended last week with gains of 3 percent to 4 percent. The Dow and S&P 500 both closed above key technical levels for the first time since Nov. 6, which could provide additional support. The Dow ended above 13,000, while the S&P broke above 1,400.
"I think the concerns (regarding talks on Greece and U.S. fiscal cliff) are just an excuse for the market to book profits after Friday's surge. We are seeing technical adjustments today," said Peter Cardillo, chief market economist at Rockwell Global Capital in New York. Continued...