Boeing gained in early New York trading after the aerospace giant reported quarterly profit above estimates and hiked its full-year forecast. PepsiCo rose after the beverage maker reported revenue that topped expectations.
It should be a quiet day for economic news from the U.S., with just the weekly mortgage approvals figures due for release.
Apple shares rose early on Wednesday, after the technology giant posted profits that beat expectations late on Tuesday. Microsoft shares showed stronger gains after it posted revenues that were better than expected, even though its earnings per share were lower.
The S&P 500 hit a record high on Tuesday, as investors focused on upbeat home sales and inflation data rather than turmoil in Ukraine and Gaza.
Despite U.S. hopes, the European Union failed to announce tough sanctions against Russia on Tuesday in response to the downing of a civilian plane over eastern Ukraine. The EU did however announce it would widen the list of individuals and companies targeted by asset freezes and visa bans.
U.S. Secretary of State John Kerry flew to Tel Aviv on Wednesday to press for a truce in the fighting between Israel and militants in Gaza that has killed more than 600 people. U.S. and European airlines have temporarily halted flights to Tel Aviv, following a rocket attack near the airport.