SEC ends investigation of David. L. Sokol, won't pursue enforcement WASHINGTON, Jan. 4 (UPI) -- The U.S. Securities and Exchange Commission won't file insider trading charges against former Berkshire Hathaway executive David L. Sokol, his lawyer said. Sokol abruptly resigned as chairman of MidAmerican Energy Holdings, a part of Warren Buffett's Berkshire Hathaway conglomerate, and came under SEC scrutiny in 2011 after he bought shares in lubricant maker Lubrizol two months before Berkshire announced a $9 billion acquisition of the company. After the deal was announced the value of Sokol's investment rose $3 million, The Wall Street Journal reported Friday. Sokol's lawyer, Barry Wm. Levine, said the SEC informed his client it had completed it inquiry and decided not to pursue a civil enforcement action.