(Adds Siem Shipping, Carlyle, Severstal, Terna)
May 14 (Reuters) - The following bids, mergers, acquisitions and disposals were reported by 2000 GMT on Wednesday:
** Norway's Siem Shipping Inc has withdrawn its bid for French group SNCM, in a blow to environmental services group Veolia which has been trying for years to sell the loss-making operator of ferries between France and Corsica.
** U.S. private equity group Carlyle has appointed Rothschild to explore possible exit options for UK firm Integrated Dental Holdings (IDH), two sources familiar with the matter said on Wednesday, in a deal which one said could be worth between 1 billion pounds ($1.7 billion) and 1.5 billion.
** Russian steelmaker Severstal said on Wednesday it was considering a range of strategic options in relation to its North American operations.
A Russian source familiar with the matter said on Monday that Severstal had received bids from potential buyers for its operations in the United States which consist of steel plants in Dearborn, Michigan and Columbus, Mississippi.
** Italy's power grid operator Terna has submitted an expression of interest for a Greek peer, the company's financial director said on Wednesday.
** Yahoo Inc has bought Blink, a mobile messaging startup that lets users send messages that self-destruct at a time set by the sender.
** U.S. drugs wholesaler McKesson plans to offer investors who did not tender their shares in Celesio less than what it paid previously, as it seeks full control over its German peer.
** Pfizer said it would ringfence the development of important drugs if it acquired AstraZeneca, rejecting a charge from the British company that a takeover would disrupt important research and put lives at risk.
Unions representing AstraZeneca workers in Sweden called on Wednesday for the government to take a clear stand against Pfizer's offer for the firm, echoing British concerns that a deal could damage local scientific research.
** Britain's biggest sporting goods retailer, Sports Direct , is in talks to buy 30 British gyms, in a move that would mark its entrance into the health and fitness industry.
** The offer made by U.S. conglomerate General Electric to take over Alstom's power arm is "a very good opportunity" for the engineering group, French Energy Minister Segolene Royal told weekly magazine Paris Match.
** Sears Holdings Corp said it was looking to sell its 51 percent stake in Sears Canada Inc in a process that could result in all of the struggling Canadian department store operator being put up for sale.
** Austrian crane maker Palfinger has sold new shares to China's Sany Heavy Industry Co Ltd in a deal to consolidate their strategic partnership, it said on Wednesday.
** BHP Billiton is in talks to sell its Australian nickel business, the top global miner said on Wednesday, in line with its aim of simplifying the company.
** China's state-backed Citic Pacific Ltd said on Wednesday that an independent financial advisor had found the terms and conditions of its proposed acquisition of some of its parent's assets "fair and reasonable".
** The euro zone's biggest bank, Santander, is close to selling a stake in its securities custody business, worth up to 1 billion euros ($1.38 billion) as a whole, to several private equity firms, Expansion newspaper reported on Wednesday.
** A consortium that includes Singapore tycoon Ong Beng Seng and Wheelock Properties (Singapore) Ltd has increased its offer price for a stake in Hotel Properties Ltd to S$4 per share, valuing the company at around S$2.07 billion ($1.65 billion).
** Etisalat has completed its purchase of a 53-percent stake in Maroc Telecom from Paris-listed Vivendi for 4.14 billion euros, the United Arab Emirates operator said in a statement on Wednesday.
($1 = 0.7270 Euros)
$1 = 1.2519 Singapore Dollars Compiled by Neha Dimri and Mridhula Raghavan in Bangalore