Jan 12 (Reuters) - The following are the top stories in the Wall Street Journal. Reuters has not verified these stories and does not vouch for their accuracy.
* France, joined by world leaders, mounted its largest-ever demonstration on Sunday in a defiant display of unity against terrorist attacks. (http://on.wsj.com/1IDBtUP)
* Tesla Motors is on a collision course with the auto industry's giants like never before, but the CEO has no plans to stop cursing or obsessing about the tiniest design details. (http://on.wsj.com/1w9mxXU)
* A cardiac-biomarker laboratory under federal investigation cut ties with its sales-and-marketing contractor, ending a joint enterprise that has collected hundreds of millions of dollars from Medicare. (http://on.wsj.com/1tYLMlv)
* Huge levels of output have helped drive commodity prices down, and many analysts believe they will stay low: Large stockpiles remain. The slump has been devastating for some producers and companies that depend on them. (http://on.wsj.com/1C69tHr)
* After years of fighting for more trading to come back onto stock exchanges, Nasdaq OMX has approached several of the biggest banks with a proposal to take over the operation of their "dark pools." (http://on.wsj.com/1FJ6DOv)
* General Motors Co plans to use its GM Financial lending arm as the exclusive provider of subsidized leases in the United States, a move that could help boost earnings while significantly increasing the Detroit auto giant's exposure to auto loans. (http://on.wsj.com/14N4zUU)
* Merck & Co has accelerated its plans to submit new drugs for hepatitis C and lung cancer for regulatory approval, in a bid to close the gap with competitors in two lucrative segments. (http://on.wsj.com/1B8p4YM)
(Compiled by Supriya Kurane in Bengaluru)