April 25 (Reuters) - Getty Images Holdings Inc said on Tuesday Trillium Capital LLC has not provided its board with enough evidence to show that its $4-billion unsolicited bid was credible enough to "warrant engagement".

Trillium, which has no public record of major acquisitions and holds over 500,000 Getty shares, had on Monday offered $10 per Getty share after asking the company to sell itself and change its strategy.

Its chief executive Scott Murray also told Reuters that his bid for Getty was genuine and that he made the offer public after the multimedia agency ignored the activist investor for weeks.

Murray also declined to detail how the transaction would be funded or disclose the amount of assets that his firm manages.

Getty on Tuesday said that due to the absence of further details from Trillium, the company believes its current management and strategy represent "the best way forward".

Trillium did not immediately respond to a Reuters request for comment. Getty's shares were down 9% in extended trading.

(Reporting by Aditya Samal in Bengaluru; Editing by Arun Koyyur)