(Adds Siemens, Pfizer, Sanofi, Club Med, Rosneft and others; updates Alstom)
April 29 The following bids, mergers, acquisitions and disposals were reported by 2000 GMT on Tuesday:
** U.S. drugmaker Pfizer will need to raise its bid for AstraZeneca to around $105 billion-$110 billion and increase the proportion of cash in the offer to win its British rival, investors believe.
** The euro zone's biggest bank Santander launched a buyout offer for the remaining 25 percent of its Brazilian unit, cementing its grip on a key profit driver in a deal that could be worth up to 4.7 billion euros ($6.51 billion).
Santander will also look at acquiring government-owned Catalunya Banc when it comes up for auction, Chief Executive Javier Marin said at a news conference.
** Germany's Siemens AG is considering paying just under 1 billion euros ($1.38 billion) for a unit of Britain's Rolls-Royce that makes equipment for the oil and gas industry and power-generation gear for utilities, sources familiar with the matter said.
** French investment firm Ardian is to buy a $1.3 billion private equity portfolio from U.S. company GE Capital, the companies said on Tuesday, in the largest secondary private equity transaction over the last year.
** Australian oil and gas producers Horizon Oil Ltd and Roc Oil Company Ltd have agreed to merge to form a single, Asia-focused energy company worth A$800 million ($741 million), the two companies said on Tuesday.
** Saipem has won a 400 million euro ($554 million) contract to help build the second line of Russia's strategic South Stream offshore gas pipeline, designed to end its reliance on Ukraine as a transit state, it said on Tuesday.
** U.S. chipmaker Cirrus Logic Inc has agreed a deal to buy British microchip maker Wolfson Microelectronics for 291 million pounds ($489 million) to boost its audio division, the two firms said.
** Industrial and Commercial Bank of China Ltd has agreed to buy a 75.5 percent stake in Turkey's Tekstil Bankasi for $316 million, as the world's biggest lender seeks to benefit from the rising trade between the two countries.
** Ras Al Khaimah Ceramics said its founding shareholder had agreed to sell 30.6 percent of his stake in the company to Samena Limestone Co, a company incorporated under the laws of the Cayman Islands.
** Italian broadcaster Mediaset is in talks with foreign investors that could potentially lead to an industrial partnership for its pay-TV business, a senior official said on Tuesday, but repeated that the unit was not for sale.
** Czech electricity producer CEZ may consider regional acquisitions after it scrapped a tender worth up to $15 billion to build new units at its Temelin nuclear power plant, Chief Executive Daniel Benes was quoted as saying on Tuesday.
** American Realty Capital Properties Inc and NorthStar Realty Finance Corp said they were not currently in merger talks, a day after reports that American Realty was looking to buy the real estate financing company.
** Itau Unibanco Holding SA said on Tuesday it would become Brazil's largest lender of payroll-deductible loans after extending the scope of a joint venture with Banco BMG SA on the segment, according to a securities filing.
** Indian generic drugmaker Wockhardt Ltd denied on Tuesday a media report that said U.S. drugmakers Mylan Inc and Pfizer Inc were in talks with the company to buy some of its assets.
** Alliant Techsystems Inc, the world's largest ammunition maker, said it would merge with Orbital Sciences Corp , after spinning off its sporting gun business.
** A group of Czech businessmen denied they were in talks to buy Central European Media Enterprises or its Czech subsidiary, as a newspaper reported on Tuesday.
** French drugmaker Sanofi is not looking at selling its animal health business, but could look at making it bigger instead, Chief Executive Chris Viehbacher told analysts on a call on Tuesday.
** A bid for French holiday operator Club Med by China's Fosun International and French private equity firm Ardian will close next month after a court rejected a shareholders' challenge that had delayed the deal by nearly a year.
** Russia's top crude oil producer Rosneft said on Tuesday that it aimed to complete deal to buy the majority of global physical oil trading operations from Morgan Stanley in the second half of 2014, as expected.
** Russian oil-to-telecoms conglomerate Sistema said on Tuesday the company and its telecoms subsidiary MTS would each pay $75 million for 10.8 percent stakes in e-commerce company Ozon.
** The owner of Raiffeisen Lower Austria-Vienna, one of the six Austrian banks to come under direct supervision of the European Central Bank this year, said on Tuesday that it planned to sell its renewable-energy business to boost its capital.
** Privately-owned Reuben Brothers Resources Group (RBRG) said on Tuesday it had agreed to sell its metals trading division to commodity trader Gerald Group, for an undisclosed amount.
** A banking foundation that is a core shareholder in Intesa Sanpaolo said on Tuesday that it was handing management of its stake in Italy's biggest bank to an asset manager to help spread the risks of its investments.
** Talks between Etihad Airways and Alitalia are continuing over a possible investment by the Abu Dhabi-based airline in Italy's troubled carrier, Italian Transport Minister Maurizio Lupi said on Tuesday.
** A plan by Malaysian state-owned oil firm Petronas to build an $11 billion liquefied natural gas (LNG) export terminal on Canada's Pacific Coast gained momentum on Tuesday with China's Sinopec becoming the latest energy player to sign on to the project. Petronas said it would sell Sinopec a 15 percent stake in its Pacific NorthWest LNG export facility, along with a 15 percent stake in the northern British Columbia shale gas assets that would feed it.
** Estonia's government decided on Tuesday to start talks on buying shares in its national gas grid, majority owned by Germany's E.ON and Russia's Gazprom, local media reported.
** Germany's Siemens said on Tuesday it would make an offer to French engineering group Alstom if it is given four weeks to examine its books and draw up a detailed plan to rival a move by General Electric. ($1 = 0.72 euros) ($1 = 0.59 British pounds) ($1 = 1.08 Australian dollars) (Compiled by Avik Das and Ankit Ajmera in Bangalore)