April 25 (Reuters) - Vivendi:
* Vivendi's chief executive Arnaud de Puyfontaine says a merger with advertising group Havas would 'make sense'
* Vivendi Chief Operating Officer Stephane Roussel says group aims to accelerate expansion in video games sector, with potential acquisitions
* Vivendi General Counsel Frederic Crepin says group received valuation estimates for Universal Music Group of about 20 billion euros
* Vivendi Chairman Bollore says talks with telecoms operator Orange only focus on potential commercial agreements
* Bollore says priority for group is to boost share price through higher results, not dividends Further company coverage: (Reporting by Mathieu Rosemain and Gwenaelle Barzic)