(Adds Colbun, Nexen Energy, Griffin Real Estate, Zinjin, Amer Sports, Sterigenics; updates Tenet, Ivanhoe Mines, Humana))
March 23 (Reuters) - The following bids, mergers, acquisitions and disposals were reported by 2000 GMT on Monday:
** China National Chemical Corp (ChemChina) is to buy Pirelli, the world's fifth-largest tyre maker, in a 7.1 billion euro ($7.7 billion) deal that will place one of the symbols of Italy's manufacturing industry in Chinese hands.
** Royal Bank of Scotland is to sell up to $3.3 billion more shares in its U.S. bank Citizens to cut its stake to less than half and accelerate its retreat to its home UK market.
** Private equity firm Warburg Pincus LLC has agreed to acquire a majority stake in Sterigenics International LLC in a deal that values the U.S. provider of contract sterilization services at more than $2 billion, including debt, a source familiar with the transaction said.
** Austrian anti-trust authorities have approved Deutsche Wohnen's offer to buy Austrian real estate peer Conwert for 1.2 billion euros ($1.31 billion), according to a document from competition watchdog BWB seen by Reuters.
** Optimal Payments Plc said it would buy Sentinel Topco Ltd and its units, known as Skrill Group, for an enterprise value of about 1.1 billion euros ($1.19 billion) to expand its online payment and digital wallet services.
** Ireland's transport minister on Monday said talks with British Airways owner IAG on a bid for Aer Lingus were "workmanlike and constructive" and that he expected the cabinet to decide whether to back the bid within weeks.
International Consolidated Airlines Group (IAG) made a 1.36 billion euro ($1.5 billion) bid for Aer Lingus in January and the Irish carrier's board recommended the offer to shareholders.
** Health insurer Humana Inc said on Monday that it would sell its Concentra urgent care and physical therapy services unit for about $1 billion to private equity firm Welsh, Carson, Anderson & Stowe and Select Medical Holdings Corp .
** Tenet Healthcare Corp said it would become the largest U.S. provider of outpatient surgery services through a joint venture with United Surgical Partners International and expects to fully own the company within five years.
** Chinese e-commerce company Alibaba Group is investing in the funds of Jerusalem Venture Partners (JVP), one of Israel's leading venture capital groups. The Calcalist financial newspaper said on its website the investment amounted to tens of millions of dollars.
** Australia's Village Roadshow Ltd, operator of the country's biggest cinema chain and several theme parks, said it will form a $500 million joint venture with China's CITIC Ltd to invest in theme parks on the mainland.
** Poland's state-run post Poczta Polska said it was interested in buying 25-percent stake in Bank Pocztowy from the country's biggest bank PKO BP to gain full control over the smaller lender, the post's chief executive said on Monday.
** Nordex is not opposed to potential takeover attempts, Chief Executive Juergen Zeschky told reporters on Monday, adding the group would be open to being bought up if it makes sense from a strategic and operational point of view.
** Hotel Shilla Co Ltd said it would buy a 44 percent stake in U.S. in-flight duty free retailer DFASS for $105 million, the latest push abroad by a South Korean duty free store operator amid intensifying competition at home.
** Austrian property group Immofinanz AG plans to offer 18.50 euros ($20) per share for a stake of up to 29 percent in CA Immobilien, turning the tables on its rival, which is seeking to increase its stake in Immofinanz.
** Nippon Steel & Sumitomo Metal Corp, Japan's top steelmaker, has signed a contract with Idemitsu Kosan Co Ltd to buy a 10 percent stake in its Boggabri coal mine in Australia. The value of the deal was not disclosed.
** Dairy Crest Group Plc said the sale of its dairy operations was being referred back to the UK Competition and Markets Authority (CMA) by the European Commission for review. Britain's largest dairy food company said the deal to sell the operations to Müller UK & Ireland Group remained on track.
** Spanish and Belgian gas transmission companies Enagas and Fluxys said they had agreed to buy Swedish operator Swedegas. While the companies did not give details about the full value of the deal, they said that each company would invest 100 million euros ($108.1 million) of their own capital, with the rest of the transaction price covered with debt.
** Taiwan's Cathay Financial Holding Co Ltd will take over two loss-making local life insurance companies, a government regulator said Monday. The government will pay T$30.3 billion ($963.77 million) to Cathay for the takeover of Singfor Life Insurance Co and Global Life Insurance Co, an official with the Taiwan Insurance Guaranty Fund told Reuters.
** Dubai's Arabtec plans to sell four of its five Saudi Arabian units, the builder's annual results show despite also stating that one of its main aims this year is to expand its activities in the kingdom.
** Finnish sporting goods group Amer Sports will buy U.S. baseball brand Louisville Slugger for $70 million to step up growth at its ball sports unit, it said on Monday.
** BDO Unibank Inc, Philippines' largest lender, said it is not bidding for industrial conglomerate San Miguel Corp's controlling stake in mid-sized lender Bank of Commerce.
** U.S. private equity firm Bain Capital LLC plans to acquire Japan Wind Development Co Ltd through a tender offer in a deal worth up to 9.7 billion yen ($81 million), the Nikkei business daily reported on Monday.
** China's Zijin Mining Group is set to buy a 9.9 percent stake in Ivanhoe Mines Ltd for about C$105 million ($83 million) and is in "detailed" talks on jointly developing Ivanhoe's copper project in central Africa, the two companies said on Monday.
** Qatar Investment Authority and Swiss travel retailer Dufry are teaming up to bid for Italian travel retailer World Duty Free (WDF), which belongs to the Benetton family, two sources familiar with the matter told Reuters on Monday.
** Canadian miner Noront Resources Ltd said on Monday that it would buy Cliffs Natural Resources Inc's chromite assets in the northern Ontario Ring of Fire district for $20 million, financed by a loan from Franco-Nevada Corp .
** Chinese automaker BAIC Motor Corp Ltd plans to deepen its partnership with Daimler AG by taking a 35 percent stake in the German firm's Mercedes-Benz Leasing Co, they said in a joint statement on Sunday.
** Spain's Santander said it had presented a non-binding offer for Portugal's Novo Banco, the successor to rescued Banco Espirito Santo (BES), in the second phase of a sale process that has attracted 14 other potential bidders.
** Luxembourg's Griffin Real Estate and U.S. investment fund Pimco plan to raise their stake in Polish business space developer Echo Investment to 66 percent, they said on Monday.
** Nexen Energy, a wholly owned subsidiary of China's CNOOC Ltd, is closing its crude oil trading division following a round of job cuts announced last week, four market sources said on Monday.
** Chilean energy firm Colbun said it is considering bidding for the controlling stake in electricity generator Isagen that the Colombian government is putting up for sale.
$1 = 0.92 euros $1 = T$31.44 $1 = 120.01 yen Compiled by Rohit T.K. and Yashaswini Swamynathan in Bengaluru