Stocks in the news: Berkshire Hathaway, Time Warner, Toyota

Berkshire Hathaway (BRK.A) credit rating was downgraded from the top "AAA" rating too "AA+" by Fitch, saying "AAA" ratings are not appropriate for financial-oriented companies in the current economy. Its senior unsecured debt rating it cut to AA from AAA. The agency also has concerns about equity and derivative investments and Buffett's tight control of the company.

Time Warner's (TWX) AOL named Google executive Tim Armstrong as its new CEO. Armstrong will also act as chairman. According to the AP, "This shakeup could mean a spin-off of AOL is more likely. Time Warner CEO Jeff Bewkeshas said he's open to a merger or sale of AOL, and in a statement Bewkes said Armstrong would be 'helpful in helping Time Warner determine the optimal structure for AOL.'" AOL is DailyFinance's parent. TWX shares are up 2 percent in premarket trade.