Check out which companies are making headlines before the bell on Tuesday:
Smithfield Foods — The pork producer will study the letter sent by major shareholder Starboard Value earlier in the day. That letter proposed a breakup of the company, saying it yielded far more value than the $34 per share buyout deal struck with China's Shuanghui Holdings.
Sony — Hedge fund operator Third Point raised its stake to 7 percent from about 6.3 percent. Third Point also asked for the chance to present its case for a spin-off of Sony's entertainment unit to the board of directors.
Boeing — Boeing formally launched a new version of its Dreamliner, the 787-10, and announced commitments for 102 of the jets from five customers including United Airlines.