The US bourse is set to open higher as European leaders get ready to meet.

New York - US stocks Tuesday opened lower ahead of the unofficial start of second-quarter earnings season and after US drugmaker AbbVie raised its informal offer to buy Irish company Shire Pharmaceuticals.

Five minutes into trade, the Dow Jones Industrial Average fell 77.13 points (0.45 percent) to 16,947.08.

The broad-based S&P 500 declined 7.62 (0.39 percent) to 1,970.03, while the tech-rich Nasdaq Composite Index lost 15.53 (0.35 percent) at 4,436.00.

Earnings season kicks off after the markets close Tuesday with the release of a report from aluminum producer Alcoa.

The giant bank Wells Fargo reports Friday.

The companies in the S&P 500 are expected to report earnings 6.5 percent higher than in the year-ago period, according to a report by S&P Capital IQ.

However, of the 117 companies to provide pre-earnings commentary, only 14 have been positive or in-line with expectations, while 102 have been negative.

AbbVie raised its informal bid to 51.15 pounds ($87.56) from 46.26 pounds ($79.19) after Shire previously rejected the offer as undervalued. - Sapa-AFP