European stocks rose for a second straight day Wednesday, as investors largely ignored the official commencement of the U.K.'s negotiations to break from the European Union, dubbed Brexit.

U.S. stocks ended Wednesday's lackluster session mostly higher, with the Nasdaq Composite logging its fourth consecutive daily gain. A rally in energy shares following a gain in oil prices CLK7, +0.08% helped the S&P 500 finish in positive territory.

Stock markets were broadly down early Thursday following a mixed session in the U.S. overnight, though shares in Australia outperformed the rest of the region thanks to firmer oil prices. But the declines have been mild so far, as markets largely shrugged off headlines noting the official start of a two-year countdown for the U.K.'s divorce from the European Union. Meanwhile, better-than-expected U.S. oil data buoyed energy-related stocks.