UPDATE 1-Brazil's review of Bayer's Monsanto takeover may be extended

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SAO PAULO, Nov 22 (Reuters) - Brazil's antitrust agency Cade could extend by as much as 90 days its analysis of the proposed takeover of seeds company Monsanto Co. by Bayer AG , according to a regulatory filing posted on the watchdog's website on Wednesday.

This could in turn push back until late March a ruling from the agency.

The analysis extension will be discussed at a session of Cade's tribunal later in the day, a Cade spokesperson told Reuters, as this is a requirement for prolonging the review.

The $66 billion Bayer-Monsanto transaction, announced in September 2016, would create the world's largest integrated pesticides and seeds company.

In February, as Bayer disclosed financial results, it said the company remained confident it could obtain the regulatory clearances and close the transaction before the end of 2017.

An extension of Cade's in-depth review may push a decision to March 20. A ruling was initially expected in late December.

Under Brazilian law, Cade has a maximum of 330 days to make a final decision on any merger. Its review of the Bayer-Monsanto deal started on April 24.

Last month, a unit of Cade said Bayer's proposed takeover of Monsanto Co. could be detrimental to competition and urged conditions for Brazilian approval of the tie-up.

Brazil is Monsanto's biggest market outside of the United States. (Reporting by Ana Mano; Editing by Cynthia Osterman and Frances Kerry)