Task: Question Generation
Input (English): Following a tentative agreement on by December 1, on December 3, 2009, the parties announced that Comcast would buy a controlling 51% stake in NBCUniversal for $6.5 billion in cash and $7.3 billion in programming. GE would take over the remaining 49% stake in NBCUniversal, using $5.8 billion to buy out Vivendi's 20% minority stake in NBCUniversal. On January 18, 2011, the FCC approved the deal by a vote of 4 to 1. The sale was completed on January 28, 2011. In late December 2012, Comcast added the NBC peacock symbol to their new logo. On February 12, 2013, Comcast announced an intention to acquire the remaining 49% of General Electric's interest in NBCUniversal, which Comcast completed on March 19, 2013.
Output (English): On what date was Comcast's purchase of controlling interest in NBCUniversal reported?