(Updates Oi SA; adds Dow Chemical, Tyson and others)
Aug 27 (Reuters) - The following bids, mergers, acquisitions and disposals were reported by 2000 GMT on Wednesday:
** Brazil's Grupo Oi SA unveiled plans to take over Telecom Italia's local mobile unit, in a move sources said was aimed at breaking up the country's second-biggest wireless carrier and upstaging merger bids by foreign rivals.
Oi said it hired Brazilian investment bank and shareholder Grupo BTG Pactual SA to explore alternatives to acquire Telecom Italia SpA's 67 percent stake in TIM Participações SA, the country's second-biggest wireless carrier.
** Dow Chemical Co has kicked off a processes to sell two of its specialty chemical subsidiaries that could fetch close to $2 billion combined, according to people familiar with the matter, part of its effort to divest several billion dollars worth of non-core assets by 2015.
** HSBC Holdings Plc and two Indian investment banks will manage the Indian government's planned stake sale in hydropower producer NHPC Ltd, two sources with direct knowledge of the deal said on Wednesday.
IDFC Capital Ltd and Edelweiss Financial Services Ltd are the other two advisors for the sale of an 11.36 percent government stake in NHPC. The stake is worth about $436 million at the current market price.
** Tyson Foods Inc, the largest U.S. meat processor, won U.S. antitrust approval for its purchase of Hillshire Brands Co, the U.S. Justice Department said.
** A former chief executive of major Dubai construction firm Arabtec said he was in talks to sell a part of his stake to Abu Dhabi's Aabar Investments and wanted over 5 dirhams per share, about 4 percent above the current market price.
** Private equity firm Terra Firma Capital Partners is looking to sell the Garden Centre Group two years after buying the business, Bloomberg reported on Wednesday, citing people familiar with the matter.
Terra Firma has held talks with potential advisers about a sale or a public floatation, which could value the company at up to 700 million pounds ($1.16 billion), Bloomberg said.
** Ratan Tata, the former chairman of India's salt-to-steel Tata conglomerate, has bought a stake in Indian online retailer Snapdeal, the company said, joining a list of funds who have invested in the country's growing e-commerce industry.
Snapdeal did not give the size or financial details of the deal.
** German property company IVG Immobilien is planning a new attempt to sell The Squaire, the office and hotel building perched on top of the train station at Frankfurt airport, a source familiar with the process told Reuters.
According to the most recent figures available, The Squaire had a book value of 800 million euros ($1.06 billion), against building costs of over 1 billion euros in the company's 2012 accounts.
** Juice maker Cutrale and investment firm Safra Group questioned a decision by Chiquita Brands International Inc's board to reject their $611 million takeover bid in favor of a merger with Ireland's Fyffes Plc, saying the move will destroy shareholder value and face unnecessary headwinds.
** The board of Spain's Telefonica is set to meet to decide on an improved offer for Vivendi's Brazilian broadband unit GVT, a source familiar with the situation said, potentially topping an expected 7 billion euro ($9.2 billion) offer from Telecom Italia.
** Royal Dutch Shell PLC has sold some of the four oil fields up for grabs in Nigeria, it said, as the oil and gas company pushes ahead with global asset sales to cut costs. No details were available on the value of the deals signed, nor when the full process will be completed.
** Ryanair Holdings PLC has moved a step closer to making an offer to buy Cyprus Airways and may make a firm offer early next year if this is approved by the Cypriot government.
** Allergan Inc said on Tuesday that it has scheduled a special shareholders meeting for Dec. 18, when activist investor Bill Ackman, who supports a hostile bid for the company by Valeant Pharmaceuticals Inc, will attempt to oust most of its board.
** Venture capital firm Kleiner Perkins Caufield & Byer has agreed to invest in fast-growing messaging startup Snapchat at a valuation close to $10 billion, the Wall Street Journal reported on Tuesday, citing people with knowledge of the matter.
** Vietnam Airlines is in talks with several partners to sell a 20 percent stake after it launches an initial public offering to raise 1.5 trillion dong ($70 million) later this year, ahead of a stock listing that could be overseas, it said on Wednesday.
** Global private equity firm Carlyle Group is in advanced talks with China Vanke Co Ltd, the country's largest property developer, to buy stakes in nine of its shopping malls, two people with direct knowledge of the matter told Reuters. One source said the deal was valued at between 6-7 billion yuan ($976 million to $1.14 billion), while the other said it could be worth up to 10 billion yuan.
** Spanish energy company Repsol SA's talks to buy Canadian producer Talisman Energy Inc are in difficulty, three sources familiar with the matter said, with Talisman's North Sea assets the stumbling block.
** A former chief executive of Dubai construction firm Arabtec said he was in talks on selling some of his stake to Abu Dhabi's Aabar Investments and wanted over 5 dirhams per share, a level that is about 4 percent above the current market price. Hasan Ismaik said he was in talks with Aabar to sell part of his 27.90 percent stake.
** New Zealand's Fonterra Cooperative Group Ltd said it will take a stake in China's biggest baby food and formula maker Beingmate Baby and Child Food Co. Ltd in the dairy giant's first tie-up with a Chinese processor since its involvement in a tainted infant formula scandal in 2008.
** China's privately-held Dalian Wanda Group is set to launch a 5 billion yuan ($813 million) e-commerce joint venture with domestic internet giants Tencent Holdings Ltd and Baidu Inc, according to two sources familiar with the investment.
** Shareholders of South Korean internet portal operator Daum Communications Corp and messaging application firm Kakao Corp approved an all-stock merger between the two firms, paving the way for a back-door listing that values Kakao at over $3 billion.
** Norwegian IT outsourcer Evry ASA, which serves banks and other data-heavy clients, is considering whether to find a buyer for the whole firm, its board said, sending the shares up to a three-year high.
** Chiquita Brands International on Wednesday re-affirmed its commitment to a merger with Irish tropical fruit company Fyffes Plc and said it expected the deal to yield cost synergies of $60 million.
** Taiwan's Cathay Financial Holding Co is in talks to acquire a 20 percent stake in medium-sized Philippine lender Rizal Commercial Banking Corp amid plans to expand in Southeast Asia, people with knowledge of the discussions said. The stake could be worth around 14.3 billion pesos ($327 million) at the current share price.
** Singapore's Oversea-Chinese Banking Corporation (OCBC) and its insurance arm Great Eastern Holdings said they are in exclusive talks with a company controlled by Thai billionaire Charoen Sirivadhanabhakdi to sell their stake in United Engineers Ltd.
** Brazil's state-run power utility Eletrobras said on Tuesday it agreed to buy a 51 percent stake in power distributor Celg Distribuição for 59.5 million reais ($26.3 million).
** Poland's Alior Bank SA is selling its wholly owned drugstore chain Polbita to drug distributor Pelion SA for an undisclosed sum.
** As hopes for a last-minute buyer dim, Atlantic City's Revel casino has laid out its closure plans, from disposing of opened bottles of alcohol to cashing unredeemed poker chips. The plans, detailed in court documents, will go into effect on Sunday, marking the end of a $2.4 billion hotel-casino.
($1 = 0.76 euro) ($1 = 6.14 Chinese yuan) ($1 = 43.69 Philippine peso) (1 US dollar = 0.6033 British pound) (Compiled by Manya Venkatesh and Mridhula Raghavan in Bangalore)