Aug 15 (Reuters) - The following bids, mergers, acquisitions and disposals were reported by 1000 GMT on Tuesday:
** Warren Buffett's Berkshire Hathaway (NYSE:BRKa) Inc BRKa.N said it added a stake in Synchrony Financial SYF.N , boosting its bet on the credit card industry, and shed its investment in the company's former parent, General Electric (NYSE:GE) Co GE.N . Transocean RIG.NRIGN.S , one of the world's biggest drilling rig operators, has agreed a deal to buy Norwegian competitor Songa Offshore SONG.OL for 9.1 billion Norwegian crowns ($1.1 bln), the two companies said on Tuesday. Corvex Management threatened a proxy battle against Energen Corp EGN.N if the U.S. oil and gas producer did not agree to add the activist investor's nominees to its board. CCR SA's CCRO3.SA second-quarter net income more than quadrupled from a year earlier to 667 million reais ($209 million) after Brazil's biggest toll road operator bought its partner's stakes in a Sao Paulo subway and Rio de Janeiro roads, according to a securities filing on Monday. Activist hedge fund Corvex Management owns shares in French food group Danone SA DANO.PA worth about $400 million, viewing the world's largest yogurt maker as significantly undervalued, Bloomberg reported late on Monday, citing people familiar with the matter. Japanese insurer MS&AD 8725.T said it has agreed to buy 6.3 percent of Australian annuity provider Challenger Ltd CGF.AX for A$500 million ($393 million), to tap the growing market for managing retirement savings. Amec Foster Wheeler Plc's AMFW.L proposal to sell almost all of its upstream offshore oil and gas servicing assets may be adequate for regulatory approval of its merger with John Wood Group Plc WG.L , the UK's Competition And Markets Authority (CMA) said. German industrial gases group Linde LING.DE said the 10-week acceptance period for its proposed $74 billion merger with U.S. peer Praxair (NYSE:PX) PX.N started on Tuesday and would run through Oct. 24.