SAN FRANCISCO (Reuters) - A steep downturn in heavyweight Chinese internet stocks and recent weakness in half of the so-called FANG group have some investors worried that a key component of Wall Street's near-decade long rally may be low on fuel.

FRANKFURT (Reuters) - Volkswagen Chief Executive Herbert Diess was told about the existence of cheating software in cars two months before regulators blew the whistle on a multi-billion exhaust emissions scandal, German magazine Der Spiegel said.

NEW YORK/WASHINGTON (Reuters) - U.S. President Donald Trump asked securities regulators to explore replacing quarterly reporting requirements with half-yearly filings at the urging of executives including PepsiCo Chief Executive Indra Nooyi, reigniting a debate about how often companies should give financial updates to investors.

NEW YORK (Reuters) - Less reporting by U.S. corporations could put shareholders in the dark, allow companies to drift off course and even make U.S. stocks less attractive and create less public company investment, some investors and analysts argue.

SAN FRANCISCO (Reuters) - The U.S. government is trying to force Facebook Inc to break the encryption in its popular Messenger app so law enforcement may listen to a suspect's voice conversations in a criminal probe, three people briefed on the case said, resurrecting the issue of whether companies can be compelled to alter their products to enable surveillance.

BEIJING (Reuters) - Chinese automaker Geely has agreed to extend its existing partnership with Proton Holdings Berhad to upgrade the Malaysia carmaker's line-up of cars and power Proton go beyond Malaysia, part of an ongoing effort to help Proton establish a presence in China and other international markets.

(Reuters) - Tesla Inc's shares slumped 9 percent on Friday after Chief Executive Officer Elon Musk told the New York Times he was under major emotional stress and was preparing for "extreme torture" from short sellers.

(Reuters) - Walmart Inc has asked some beauty suppliers to consider sourcing products from outside China, as it looks for ways to mitigate the impact of a new set of tariffs on Chinese products proposed by the Trump administration.

WASHINGTON (Reuters) - A company owned by Elon Musk that is trying to lower the cost of building high-speed transit tunnels has asked the Trump administration to exempt it from tariffs for some Chinese-made tunnel boring machine components, warning the tariffs could significantly delay a planned tunnel between New York and Washington.