(Adds Embraer, Niki, Immofinanz, 9mobile, Melrose, Aircel, Airtel, Repsol, Aventics; Updates Tesco, Melrose)
Feb 28 (Reuters) - The following bids, mergers, acquisitions and disposals were reported by 2100 GMT on Wednesday:
** The chief executive officer of Brazilian planemaker Embraer SA, Paulo Cesar de Souza e Silva, said that he expects tie-up talks with Boeing to be finalized in the first half of this year.
** The sale of insolvent Austrian airline Niki to former motor racing champion Niki Lauda closed on Wednesday, the insolvency manager Lucas Floether said.
** Property firm Immofinanz effectively abandoned its planned merger with CA Immo on Wednesday following pressure from an activist investor, saying it is now considering selling its 26 percent stake in its Austrian rival.
** Teleology Holdings Limited has emerged as preferred bidder for Nigeria's fourth largest telecoms firm 9mobile and has been asked to pay a deposit of $50 million in March, two sources with knowledge of the deal told Reuters.
** Indian mobile carrier Aircel Ltd filed for bankruptcy on Wednesday, pressured by a high debt pile and mounting losses following a price war triggered by a telecom upstart.
** Spain's Repsol as asked Bank of America-Merrill Lynch to value its energy portfolio in the North Sea as it considers leaving a troubled joint venture with China's Sinopec , two banking sources said.
** U.S. cable operator Comcast has informally notified the European Commission of its intention to bid for Britain's pay-TV group Sky, triggering the regulatory process for the $31 billion deal.
** Buyout group Triton is preparing the sale of pneumatics parts maker Aventics, a former unit of German automotive supplier Robert Bosch, which could fetch a price of around 500 million euros ($610 million), people close to the matter said.
** India's Bharti Airtel is exploring merger and sale options for its mobile towers businesses as Chairman Sunil Bharti Mittal seeks to get out of the infrastructure game and focus on connectivity.
** A consortium of buyout groups will pay around a billion euros for Germany's HSH Nordbank, once the world's largest ship financier, as it emerges from crippling writedowns and state bailouts triggered by the deepest sector slump on record.
** German drug and crop chemical maker Bayer is set to gain conditional European Union antitrust approval for its $62.5 billion bid for world No.1 seed company Monsanto , two people familiar with the matter said.
** Bayer said it would need more time to wrap up its takeover of seeds company Monsanto after the drugmaker reported lower than expected fourth-quarter earnings which were hit by pesticide pricing pressures in Brazil.
** Tesco's 4 billion pound ($5.5 billion) takeover of Booker was overwhelmingly backed by shareholders of both companies on Wednesday, clearing the final hurdles to the creation of a new powerhouse in Britain's 200 billion pounds-a-year food market.
** Germany will investigate whether to tighten rules governing when an investor needs to disclose a holding in a company after news that China's Geely purchased a $9 billion stake in Daimler surprised the market.
** The consortium that plans to buy TDC will split the Danish telecoms company into three separately managed businesses, it said in its offer document published on Wednesday.
** Melrose Industries has secured the backing of investor advisory firm Institutional Shareholder Services (ISS) for its 7 billion pound ($9.7 billion) hostile bid for British engineering firm GKN.
** Investor adviser PIRC has told shareholders in Melrose Industries to oppose its 7 billion pound ($10 billion) bid for engineering group GKN, putting it at odds with two other proxy voting firms. ** Whitbread Plc, Britain's biggest hotel and coffee shop operator, said it had bought 19 hotels in Germany to expand its business beyond its base of Premier Inns in Britain. ** Amazon.com Inc has agreed to buy video doorbell maker Ring, the companies said on Tuesday, in what analysts see as a growing bet on delivering packages inside of shoppers' homes and on home security. ** The Chinese buyer of a Hong Kong skyscraper from billionaire Li Ka-shing in a record $5.2 billion deal has pulled out of the deal, according to two people with direct knowledge of the matter. ** TiVo Corp has started evaluating a wide range of strategic options including the possibility of going private, the set-top box maker said on Tuesday. ** EBay Inc said on Tuesday it would buy Giosis Pte Ltd's Japanese business, including the Qoo10 online shopping platform, to expand its presence in Asia's second-largest economy. ** U.S. cable giant Comcast Corp has offered $31 billion for Sky Plc, threatening a plan hatched by Rupert Murdoch's Twenty-First Century Fox Inc and Walt Disney Co to seize control of Europe's biggest pay-TV group. (Compiled by Akshara P and Uday Sampath in Bengaluru)