MILAN (Reuters) -Italy's biggest insurer Generali posted a higher profit for the first quarter, as it prepares to review a bid from its biggest investor Mediobanca to acquire the group's private banking unit Banca Generali.

Operating profit, the figure most closely watched by the market, grew 8.9% year-on-year in the quarter to 2.1 billion euros ($2.4 billion), driven by the non-life business. It was slightly ahead of a company-provided analyst consensus of 2 billion euros.

Generali's net profit came in at 1.2 billion euros, above analysts' expectations of 1.1 billion euros, despite a 4.8% drop from the same period last year when the company posted a one-off gain from a disposal.

Itself under siege by state-backed Monte dei Paschi di Siena amid an Italian banking takeover war, Mediobanca has unveiled a 6.3 billion euro proposal ($7.1 billion) to buy Banca Generali, of which Generali owns 50.2%.

The deal, which Mediobanca had long considered as a means of powering its wealth management business, would be financed by handing investors in Banca Generali the shares Mediobanca currently holds in the insurer.

Earlier this year Mediobanca became the target of an unsolicited takeover offer by smaller rival Monte dei Paschi.

Generali said gross written premiums remained largely flat in the quarter, at 26.5 billion euros, falling short of analysts' expectations. The increase in premiums in the non-life segment was offset by a 4.5% drop in the life segment.

Generali's finance chief, Cristiano Borean, told a post-results call that the decline in life insurance premiums was due to regulatory changes in Asia which triggered a buying spree for insurance products in the first quarter of 2024 and to commercial strategies the insurer introduced in Italy and France to slow down redemptions during the same period.

Generali's Solvency ratio, a measure of its financial strength, rose to 212% on Monday from 210% at the end of March, Borean said.

Generali said it was committed to hitting its 2025-2027 targets including an average annual growth of earnings per share (EPS) of 8-10%. ($1 = 0.8827 euros)

(Reporting by Gianluca Semeraro; Editing by Alvise Armellini and Valentina Za)