New York/Amsterdam, Nov. 7 (Reuters): Dutch information and media company VNU said on Monday it is in talks with US healthcare data firm IMS Health that could terminate their $7-billion merger deal after a shareholder revolt.

VNU said the talks were in response to shareholders who said they represented 48 per cent of VNU shares and who declared they would not support the transaction under any circumstances.

"The companies have discussed various possible alternatives, including a revised merger agreement as well as termination of the agreement," VNU said in a brief statement.

VNU, the world's largest market-research company, said both firms continued to believe their deal ? announced in July ? was in the best interests of their shareholders, and would move forward with the merger pending the talks on alternatives.

"A cancellation of the deal with IMS now seems very likely," Rabo Securities, which rates VNU a "buy," said in a note. Rabo said if the deal failed, VNU might return at least 1 billion euros to shareholders and change its chief executive, Rob van den Bergh. VNU might also be broken up or become a bid target for private-equity firms, it said.

"An annulment would lead to major share buybacks and dividend flow to shareholders. If the IMS deal is blocked and VNU enters into a break-up or takeover scenario, we see upside to 30 euros per share," Petercam analyst Gert Potvlieghe said.

Shareholders, who held talks with VNU last month to discuss their opposition to the merger, have said the deal is too expensive, with too much share dilution, and they want VNU to sell a big division and return more cash to investors instead.

Templeton Gobal Advisors, Fidelity Investments and Knight Vink Asset Management are leading the revolt.