March 6 (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.

* The Obama administration further postponed a provision of the Affordable Care Act on Wednesday, the latest in a series of changes that have delayed or pared back the health overhaul so much that many of its ambitious goals won't be achieved during its first years in full effect. ()

* More than 1,600 stockbrokers failed to disclose bankruptcy filings, criminal charges or other red flags in violation of regulations, without regulators noticing, according to a Wall Street Journal analysis. ()

* A crop of new lenders is jumping into the subprime personal-loan market, wooing consumers with flawed credit who have been neglected since the financial crisis. ()

* Bank of America Corp on Thursday will start offering a new checking account, capping a four-year effort to boost revenue from its most basic banking product without alienating customers and lawmakers. ()

* U.S. and European diplomats failed in a frantic, daylong effort to get Russia and Ukraine to begin direct negotiations aimed at ending Moscow's military incursion into the former Soviet state, raising the prospect of a protracted standoff. ()

* The United Nations special envoy to Crimea was threatened by a group of 15 to 20 men, some armed, who told him to leave Crimea as he was walking out of the Ukrainian naval headquarters in the regional capital on Wednesday, a senior U.N. official said. ()

* A federal probe into why General Motors Co took nearly 10 years to recall cars with a potentially deadly defect heated up on Wednesday as safety regulators demanded the auto maker answer 107 questions on its handling of a faulty ignition switch. ()

* Private-equity firm Cerberus Capital Management LP is working to sew up a deal to buy Safeway Inc this week, though its efforts to do so have been complicated by supermarket giant Kroger Co, according to people familiar with the matter. ()

* The Bank of England suspended a staff member amid an internal probe into whether officials knew about or played a role in manipulation of foreign-exchange markets, sending a global investigation of banks to the top of London's financial hierarchy. ()

* In the months before Mt. Gox's collapse, the bitcoin exchange was coming under increasing pressure from one of its banks, which complained about an unmanageable volume of money transfers and repeatedly asked the exchange to close its account with the bank, people familiar with the situation say. ()

* General Electric Co gave Chief Executive Jeffrey Immelt his second base pay raise in the 12 years since he took over, a reward for the company's 2013 performance when its stock rose more than 30 percent. ()