(Adds Cia Siderúrgica Nacional, YP Holdings LLC, Sibanye Gold, Norilsk Nickel)
April 18 (Reuters) - The following bids, mergers, acquisitions and disposals were reported by 2000 GMT on Monday:
** Cia Siderúrgica Nacional SA has asked a Brazilian court to order ailing rival steelmaker Usinas Siderúrgicas de Minas Gerais SA to tap cash from a subsidiary and revise the terms of a capital injection that was approved on Monday, according to sources. YP Holdings LLC, the digital advertising business of what was formerly called Yellowpages.com, is planning to submit a first-round bid on Monday to merge with Yahoo Inc YHOO.O , a source familiar with the matter said on Monday. South Africa's gold mining company Sibanye Gold SGLJ.J said on Monday it was disappointed by the lack of consultation over a revised black empowerment charter published by the mines ministry. Russia's Norilsk Nickel GMKN.MM said on Monday its board had approved the sale of 0.79 percent of its shares for $158 million to a company controlled by Russian billionaire Roman Abramovich and partners. Event management software maker Cvent Inc CVT.N said it agreed to be acquired by private equity firm Vista Equity Partners for about $1.65 billion in cash. The German state of Berlin plans to take a majority stake in the capital's gas network as part of a broader ownership change at natural gas supplier GASAG that will push out existing shareholders Vattenfall VATN.UL and Engie ENGIE.PA . Austria's Immofinanz IMFI.VI and CA Immo CAIV.VI announced a fresh attempt to merge to create a property group offering retail and office buildings across central and eastern Europe. China's Hebei Iron & Steel Group 000709.SZ signed a 46 million euro ($52 million) agreement to buy a loss-making Serbian steel plant in the first major privatization by Prime Minister Aleksandar Vucic's government, days before an election. U.S. oil and gas major Chevron Corp (NYSE:CVX) CVX.N has put its Myanmar gas block stakes worth an estimated $1.3 billion up for sale, banking sources familiar with the matter said, in what would mark the biggest M&A transaction involving the country's assets. Spain's Caixabank CABK.MC said it was making a fresh takeover offer worth around $1 billion for the 56 percent of Portuguese lender Banco BPI BBPI.LS that it does not already own, after a key obstacle was removed on Sunday. Hurricane Energy HUR.L has found a new investor in private equity fund manager Kerogen Capital which is injecting 44.1 million pounds ($62 million) into the company for a nearly 30 percent stake, showing some rare appetite in oil deals amid weak prices. Spain's Abertis ABE.MC said together with a unit of Canada's Brookfield Asset Management BAMa.TO , it will launch a bid for the shares of Brazil's Arteris it doesn't already own for 10.15 reais ($2.87) per share. Three consortia of Australian and international funds have submitted bids for a 50-year lease of the Port of Melbourne, Australia's biggest shipping container terminal, people familiar with the matter said. Drugmaker AstraZeneca Plc AZN.L has held internal talks about a bid for cancer treatment maker Medivation Inc MDVN.O but has yet to make a formal offer, the Sunday Times reported, citing sources. Airbus Group AIR.PA has not expressed an intention to take a stake in Russian Helicopters, an Airbus spokesman said on Sunday. Israeli conglomerate Delek Group's DLEKG.TA gas and oil exploration units, Delek Drilling and Avner Oil Exploration, are considering merging to reduce costs, attract new investors and simplify the financing process in developing the Leviathan natural gas field. Saudi Arabia's Almarai 2280.SE wants to buy a controlling stake in the United Arab Emirates' National Food Products Co (NFPC), the Riyadh-listed firm said on Sunday.