March 7 (Reuters) - French media group Vivendi on Thursday reported 7.5%growth in full-year core earnings, helped by its Havas, Canal+ businesses and the integration of Lagardère, but gave no major update on a possible split into four listed companies.

Vivendi has been looking into splitting up into several businesses, with the aim of boosting their valuation.

Yannick Bolloré, chairman of Vivendi's supervisory board, said the company was still studying the split-up option.

CEO Arnaud de Puyfontaine told journalists that he presented details of progress made on the project to the supervisory board earlier on Thursday.

"As indicated last December, the completion time for such a transaction would be 12 to 18 months," the company said.

The split would lead to separate listings for CANAL+, advertising business Havas, a company that would include publishing and distribution assets, including Lagardere, and an investment company.

"We will be very agile and we'll decide depending on the opportunities, either for disposals or new acquisitions," finance chief François Laroze told analysts in response to a question about deals for the potential new investment firm.

For 2023, earnings before interest, taxes, and amortization (EBITA) were 934 million euros ($1.02 billion), against 868 million euros posted a year earlier.

Earlier this week Vivendi raised its offer to buy all remaining shares it doesn't own in South African broadcaster MultiChoice.

Vivendi will propose an ordinary cash dividend of 0.25 euros per share for 2023, stable compared to a year ago. ($1 = 0.9141 euros) (Reporting by Chris Reese. Editing by Jane Merriman)