U.S. stock index futures pointed to a lower open on Wall Street on Wednesday, as the market braced for more corporate earnings and after a late afternoon sell-off in Chinese stocks rattled investors.

At 5.19 a.m. EST, futures for the S&P 500 were down 0.40 percent, Dow Jones futures were down 0.33 percent and Nasdaq 100 futures were down 0.20 percent.

Futures fell more than 1 percent earlier, driven lower by a 5 percent slide in Chinese shares <.SSEC> -- posting their biggest daily decline in eight months and dragging down Hong Kong-listed counters -- on worries that authorities might take measures to cool the 80 percent bull run in Shanghai this year.

Japan's Nikkei stock average <.N225> edged up 0.3 percent to a seven-week closing high, buoyed by high-tech shares such as Tokyo Electron <8035.T>, but gains were capped ahead of key company earnings, and Nippon Steel <5401.T> fell 3.5 percent after the company said it swung to a quarterly loss.

European stocks were up 0.8 percent in late morning, led by Bayer , after the company posted forecast-beating results and stuck to its target. <.EU>

Germany's SAP , the world's biggest maker of business management software, which competes with U.S. software maker Oracle , raised the outlook for its 2009 operating margin on solid second-quarter results, giving Europe's battered technology sector a glimmer of hope.

Dutch chemical group Akzo Nobel NV , the world's biggest paint group, which competes with PPG Industries
, reported a smaller-than-expected 12 percent fall in second-quarter core profit and said early indications in March that markets might be stabilizing continued into the second quarter.

Microsoft Corp and Yahoo Inc will be in focus on Wednesday, after the two companies have agreed to an online search and advertising partnership, a source familiar with the situation said.

Microsoft shares in Frankfurt were up 0.9 percent while Yahoo shares were up 1.7 percent.

After the bell on Tuesday, Western Digital Corp posted sharply better-than-expected quarterly earnings on record shipments.

Oil fell 2 percent to below $66 a barrel on Wednesday, extending losses for a second day after a sharp sell-off in buoyant Chinese shares triggered wider losses in risk assets.

The dollar and the yen gained broadly while perceived higher risk currencies came under heavy selling pressure on Wednesday as riskier assets succumbed to profit-taking after a recent strong rally.

The day's earnings calendar includes quarterly results from ConocoPhillips , Hartford Financial , Symantec , Time Warner Inc and Visa Inc , while on the macro front, the day's economic agenda includes data on durable goods orders.

The Dow and the S&P 500 edged lower on Tuesday as investors shrugged off weak consumer confidence data and focused on positive earnings reports.

The Dow Jones industrial average <.DJI> shed 11.79 points, or 0.13 percent, to 9,096.72. The Standard & Poor's 500 Index <.SPX> dropped 2.56 points, or 0.26 percent, to 979.62. But the Nasdaq Composite Index <.IXIC> gained 7.62 points, or 0.39 percent, to 1,975.51.

(Reporting by Blaise Robinson; Editing by Hans Peters)