Feb 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.
* North Korea appeared to have exploded a nuclear device Tuesday, its third experimental detonation in a long effort to build weapons of mass destruction that the U.S. and other countries consider a serious threat.
* Pope Benedict XVI will become the first pontiff in six centuries to resign, marking the end of a transitional papacy that focused more on theological and internal renewal and less on the broader challenges that face the Roman Catholic church at the start of its 21st century of existence.
* U.S. regulators are widening their probe of global interest-rate-rigging by scrutinizing what they claim is a pivotal role of two U.K. brokerage firms in the scandal, people close to the investigation say.
* The regulator that oversees the professional conduct of Britain's accountants has launched a probe into the past financial reports of Autonomy Corp, the U.K. software company that Hewlett-Packard Co purchased for $11 billion in 2011 and later accused of having made outright financial misrepresentations ahead of the deal.
* Hedge-fund manager David Einhorn has proposed that Apple Inc issue a special class of stock that would carry a high dividend yield.
* Nasdaq OMX Group Inc, long on the hunt for a partner, has ramped up its conversations about strategic options ranging from joint ventures to a sale, according to people familiar with the talks, as rival NYSE Euronext moves ahead with a merger that will form an even-bigger competitor.
* U.S. regulators told the world's biggest maker of insulin, Denmark's Novo Nordisk, that they couldn't approve a potential blockbuster diabetes drug, delaying its U.S. introduction and sending the company's shares tumbling.
* Hostess Brands Inc won permission to place a selection of its cake and bread assets, including the Twinkie brand, on the auction block as the baking company continues to sell off its business piece by piece.