June 26 (Reuters) - Brazilian power company Equatorial was the only bidder for a strategic role in water utility Sabesp, which is currently under a privatization process, reported local newspaper Valor Economico on Wednesday, citing sources.

Sao Paulo intends to privatize Sabesp through an unusual two-part share offer, maintaining a non-controlling stake, and selecting what it is calling a "strategic investor" to take a 15% stake in the firm and hold the shares at least until the end of 2029.

According to the report, another firm that had been interested in the privatization deal, sanitation company Aegea, gave up on the transaction due to a "poison pill" included in the deal to prevent the risk of a hostile takeover.

Citing sources, the report said that amid rumors of Aegea stepping out, Equatorial might have presented a less ambitious proposal to Sabesp, although no further details were given.

Equatorial said it does not talk about specific deal possibilities in answer to a Reuters request for comment. Aegea did not immediately respond.

Sao Paulo state, which is leading Sabesp's privatization process, said that finalists eligible for the role of strategic investor will only be unveiled on Friday. (Reporting by Andre Romani and Luana Maria Benedito; Editing by Stephen Coates)