(Adds details, background) BARCELONA, Feb 3 (Reuters) - Spanish mobile phone mast operator Cellnex will raise up to 7 billion euros ($8.4 billion) to fund the acquisition of telecoms tower company Hivory and significantly expand its presence in France. Since its listing in 2015, the Barcelona-based firm, which currently has a market capitalisation of 23.9 billion euros, has grown rapidly to become Europe’s largest mobile phone towers operator by buying up assets which have retained their appeal for investors thanks to their steady cash flows. In its latest major deal, Cellnex reached an agreement with Altice and Starlight Holdco to acquire Hivory, which has around 10,500 masts in France, planning an initial investment of 5.2 billion euros, it told the Spanish stock market regulator on Wednesday. “With Ivory’s acquisition, we will work in France with three of the largest mobile operators in the market, promoting the sharing of infrastructures,” Cellnex’s chief executive Tobias Martinez said in a statement. The company will control around 120,000 masts once its latest deals are finalised. The 7 billion euros capital increase, to be approved after a shareholders meeting in late March, would finance the acquisition of Hivory in France and the one announced in January for the integration of Deutsche Telekom towers and sites in the Netherlands, Cellnex said. In total, it envisages projects of up to 18 billion euros in the coming 18 months. The company said it expects the Hivory deal - which is pending regulatory approval - to increase its adjusted earnings before interest, tax, depreciation and amortization (EBITDA) by around 460 million euros. Cellnex shares closed with a 0.43% rise after dropping 2% after the announcement. J.P. Morgan, Barclays, BNP Paribas and Goldman Sachs will act as coordinators and book runners. “Cellnex is now the biggest corporate equity issuer in the last 10 years,” said a source familiar with the transaction, adding that it was the company’s fourth rights issue in recent years. “Investors have got a lot of money to put to work, so if you get fast growth due to disruption or very visible low risk growth in otherwise slow-growing sectors, such as telecom infrastructure, those are things that investors absolutely will invest in,” the source added. In November, Cellnex had unveiled its biggest purchase to date with a deal to buy 24,600 telecom towers across Europe from Hong Kong’s CK Hutchison for 10 billion euros, expecting to boost its annual revenues by around 1.2 billion euros. ($1 = 0.8317 euros) (Reporting by Joan Faus, Emma Pinedo Writing by Joan Faus Additional reporting by Abhinav Ramnarayan Editing by Ingrid Melander and Keith Weir)