SAO PAULO (Reuters) - Brazilian pulpmaker Suzano confirmed on Wednesday it is interested in assets owned by International Paper, but said that it has not reached any final decision about a deal.

Reuters reported this week that Suzano was in talks with advisers about sweetening an offer for International Paper, after approaching the U.S.-based firm to express interest verbally in an all-cash acquisition worth $15 billion.

In a securities filing answering regulatory questions about recent volatility of its shares, Suzano confirmed its interest in the assets but said that "up to the moment, there is no agreement, binding or otherwise, nor any decision or deliberation" by its management regarding a deal.

The deal would be conditioned on International Paper abandoning its recently announced agreement to acquire British packaging firm DS Smith for $7.2 billion, sources said.

In an earnings conference call after Reuters reported Suzano's initial proposal, outgoing Chief Executive Walter Schalka said its management "will not do anything that could put the company at risk".

Shares in Suzano, which fell nearly 18% since news of the talks broke until Tuesday's closing, were down an additional 0.3% in Wednesday morning trading.

(Reporting by Peter Frontini; Editing by Gabriel Araujo and Brad Haynes)