The S&P 500 and Nasdaq rose on Wednesday, lifted by positive news on online retailers such as Amazon, while the Dow edged lower with energy and financials following mixed data on the labor market.

The major stock indexes pared early gains on concerns that bank profits could be hurt under derivatives legislation being considered.

The banks don't know what the heightened financial reform is going to be. There is no clarity to regulation, said Weston Boone, vice president of listed trading at Stifel Nicolaus Capital Markets in Baltimore.

According to a Sanford C. Bernstein note, JPMorgan Chase & Co said it could see its revenue fall by as much as $3 billion under a worst case scenario under the legislation. Shares of JPMorgan, a Dow component, fell 1.3 percent to $41.67.

In mixed news on the crucial labor market, U.S. private employers shed 169,000 jobs in November, fewer than the 195,000 that were cut in October, though the report came in worse than expected, according to the ADP National Employment private sector survey.

January crude oil futures sank 2.3 percent to $76.59 per barrel after U.S. government inventory data showed a surprising build in crude and gasoline stockpiles, pressuring energy shares.

The S&P Energy index <.GSPE> fell 0.8 percent and was the worst performer among S&P sectors. Occidental Petroleum shed 1.8 percent to $80.73.

The Dow Jones industrial average <.DJI> fell 15.27 points, or 0.15 percent, to 10,456.31. The Standard & Poor's 500 Index <.SPX> inched up just 0.15 point, or 0.01 percent, to 1,109.00. The Nasdaq Composite Index <.IXIC> gained 11.34 points, or 0.52 percent, to 2,187.15.

Amid continued questions about retailers' strength in the holiday shopping season, online vendors were strong performers after analytics firm comScore said that Cyber Monday sales were up 5 percent from the previous year.

Shares of jumped 2.6 percent to $142.14 on Nasdaq.

(Editing by Jan Paschal)