Mark Zuckerberg and Xiaomi Inc CEO Lei Jun discussed a potential investment by Facebook in China's top smartphone maker ahead of its $1.1 billion fundraising last month, but a deal never materialized, several people with knowledge of the matter told Reuters.

Roche has boosted its efforts to tackle antibiotic resistance, striking a deal worth up to $750 million with Japan's Meiji Seika Pharma and Canada's Fedora for a drug that can restore the power of antibiotics to combat infections.

U.S. small business optimism jumped in December to its highest level in more than eight years, the latest sign of strength in the economy even as dark clouds settle over global growth.

MetLife Inc (MET.N) on Tuesday sued U.S. regulators over a decision to subject the insurer to tougher oversight because it harbors enough risk to endanger the financial system if the next crisis hits.

U.S. stocks ended down slightly in a volatile session on Tuesday, led by a drop in materials and energy shares following further weakness in commodity prices.

Investors had hoped that the biggest U.S. banks would boost dividend payments substantially in 2015, but recent events including slumping oil prices will make it harder for banks to pay out more.

Brent and U.S. WTI crude oil prices fell to their lowest levels in almost six years on Tuesday as a big OPEC producer stood by the group's decision not to cut output to tackle a glut in the market.

A diplomatic push by Venezuela and Iran for an OPEC oil output cut has failed to soften the refusal of the group's Gulf members to do so for now, delegates said on Monday.

United Airlines is assessing whether to outsource jobs at airports around the country in a cost-cutting effort that could impact some 2,000 workers.

Huawei Technologies Co Ltd likely booked a 17 percent increase in operating profit last year, as worldwide adoption of fourth-generation (4G) mobile technology boosted earnings at China's leading telecommunications equipment maker.