Stocks rose in a zigzag session on Wednesday as gains in major tech shares helped offset worries whether euro zone leaders can make progress in easing the region's debt crisis.

Comments about possible new euro zone bonds to help ease the region's debt crisis spurred early optimism, prompting an early rally in equities. However, those initial gains faded after an Austrian parliamentary panel failed to pass changes to a bailout fund, possibly delaying government approval until October.

The Dow fell as much as 1 percent, although officials said approval was not endangered.

All the cross-currents in Europe are resulting in increased volatility here, said David Kotok, chief investment officer at Cumberland Advisors in Sarasota, Florida. When we know what the next step will be, that will resolve a lot of our issues here.

The leaders of Greece, France and Germany were to hold a video conference on measures to head off a potential Greek default, which has prompted rising global alarm.

Tech stocks were the biggest gainers, with the S&P information technology index <.GSPT> up 0.8 percent and the semiconductor index <.SOX> up 1.5 percent. They are seen as a safer bet in risky times, as well as an industry that will benefit as the economy recovers.

Nvidia Corp and SanDisk Corp were the index's top gainers, with Nvidia up 4.9 percent to $15.24 and SanDisk climbing 4 percent to $42.60.

Dell Inc added 2.3 percent to $14.71 a day after its board authorized an additional $5 billion stock buyback program.

The yin and yang of the market right now is that stocks are cheap from a long-term perspective, but the uncertainty overseas means the tone changes all the time, Kotok said.

The Dow Jones industrial average <.DJI> was up 49.15 points, or 0.44 percent, at 11,155.00. The Standard & Poor's 500 Index <.SPX> was up 6.57 points, or 0.56 percent, at 1,179.44. The Nasdaq Composite Index <.IXIC> was up 23.36 points, or 0.92 percent, at 2,555.51.

Also lifting the Nasdaq was Cisco Systems Inc , which rose 0.9 percent to $16.49. The company slashed its long-term forecasts late Tuesday, but the stock rose on the view it was seeking to reduce costs and set itself on a path for slower but more stable growth.

Avis Budget Group rose 4.5 percent to $12.27 after dropping its bid to buy Dollar Thrifty . Hertz Global Holdings Inc , which has also bid for Dollar, surged 12 percent to $11.22.

In the latest U.S. economic data, growth in retail sales stalled in August while business inventories rose slightly less than expected in July, suggesting caution by firms about demand at the start of the third quarter.

(Editing by Kenneth Barry)