U.S. stocks mixed midday amid Greek uncertainty

U.S. stocks swung narrowly around flatline in the morning session Thursday, as investors continued to meditate on the impact of negotiations over Greece's bailout.

At noon, the Dow Jones Industrial Average lost 20.32 points, or 0.11 percent, to 18,009.53. The S&P 500 edged up 0.71 point, or 0. 03 percent, to 2,100.39. The Nasdaq Composite Index added 18.01 points, or 0.37 percent, to 4,924.37.

Germany rejected a request from Greece Thursday to extend its loan agreement with eurozone creditors, saying the Greek proposal did not meet previous agreed criteria decided by the Eurogroup Monday.

Earlier on Thursday, Greece submitted a request to the Euro Working Group for a six-month extension of the four-year bailout loan agreement in a bid to receive vital financial aid from the eurozone after the current bailout expires on Feb. 28.

A renewed oil slump also added negative sentiment to the market. According to data from the U.S. Energy Information Administration, U.S. oil stockpiles increased by 7.7 million barrels last week, exceeding market estimates. U.S. oil price slipped below 50 dollars a barrel in early morning session before paring part of losses to trade above 51 dollars a barrel around midday Thursday.

However, U.S. weekly jobless claims came out positive. In the week ending Feb. 14, the advance figure for seasonally adjusted initial claims decreased 21,000 from the previous week's unrevised level to 283,000, lower than market consensus of 290,000, said U.S. Labor Department Thursday.

Wall Street also continued to digest minutes of the Fed's January policy meeting released Wednesday, which showed that more Fed officials leaned toward keeping rates at zero "for a longer time" than wanted an earlier move.

In corporate news, shares of Wal-Mart declined 2.65 percent around midday Thursday after the world's largest retailer reported adjusted earnings that beat estimates and revenue that missed expectations. Endite