** Shares of Spanish insurance company Grupo Catalana Occidente GCO.MC rise about 17% after its majority shareholder Inoc launched a bid to buy the shares it does not yet own
** Inoc, which already holds 62.03% stake in the company, is offering 50 euros ($53.93) per share, which represents a premium of about 18% versus Thursday's closing price
** Shares are on track for their best day ever
** Friday's gains add about 850 million euros to the group's market cap which now stands at about 5.1 billion euros
(Reporting by Joao Manuel Mauricio)
((JoaoManuel.VicenteMauricio@thomsonreuters.com))