Sept 3 (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 extremist group Islamic State posted a video purporting to show the beheading of American journalist Steven Sotloff, bringing calls for the U.S. to more forcefully confront the militants in both Iraq and Syria. (http://on.wsj.com/1nV1kxG)
* California regulators want PG&E Corp's utility to pay $1.4 billion in fines and penalties over a fatal natural-gas pipeline explosion in San Bruno, California. The state Public Utilities Commission proposed fining Pacific Gas & Electric Co $950 million over allegations that the company violated federal and state pipeline safety rules before the 2010 pipeline explosion. (http://on.wsj.com/1ly45JF)
* Private-equity firm KKR & Co LP said Tuesday it agreed to buy a minority stake in Savant Systems LLC, a closely held Hyannis, Massachusetts, company that sells systems that let homeowners control everything from thermostats and stereos to lighting and lawn sprinklers, from their smartphones. KKR is leading an investment of about $90 million in the company and the firm will have a roughly 35 percent stake in Savant, according to a person familiar with the matter. (http://on.wsj.com/1BaH17E)
* Home Depot Inc is working with banks and law enforcement agencies to investigate a potential breach of customer credit- or debit-card data. The home-improvement retailer said on Tuesday it is looking into what it called unusual activity and said that if it confirms a breach occurred, it will immediately notify customers. (http://on.wsj.com/1nwyEem)
* A key employee leading Google Inc's efforts to beam Internet access from satellites has abruptly left the company and is now working closely with Space Exploration Technologies Corp and its founder Elon Musk, according to people familiar with the matter. (http://on.wsj.com/1tsh3LA)
* The Federal Bureau of Investigation hasn't found any evidence to suggest the hacker or hackers who successfully penetrated the computer system at JPMorgan Chase & Co scored any similar successes against other big U.S. banks, four people close to the investigation said. (http://on.wsj.com/1pGzVFa)
* IEX Group Inc, an upstart private trading venue launched less than a year ago, plans within a week to seek U.S. regulatory approval to become a full-fledged stock exchange, according to people familiar with the company's plans. (http://on.wsj.com/1lH58HC)
* An internal Credit Suisse Group AG investigation into allegations of inappropriate employee behavior has roiled the bank's European stock-trading desk, according to people familiar with the probe, in the latest example of a major bank uncovering potential problems as it sifts through employees' electronic communications. (http://on.wsj.com/1ux5LTD)