UPDATE 3-Brazil ANP head criticized over oil field estimate

(Adds fresh Petrobras comments, paragraphs 9-10)

RIO DE JANEIRO, April 15 (Reuters) - Brazil's stock market regulator criticized the head of the National Petroleum Agency (ANP) for stating reserve estimates of a potentially giant oil find and federal prosecutors said on Tuesday they may investigate.

The government's ANP has distanced itself from a statement made on Monday by its chief, Haroldo Lima, which put Carioca field reserves at 33 billion barrels of oil equivalent, citing data obtained informally from Brazil's state-run oil company Petrobras (PETR4.SA: Quote, Profile, Research, Stock Buzz)(PBR.N: Quote, Profile, Research, Stock Buzz).

The Rio de Janeiro federal public prosecutors' office said it would analyze media reports on Lima's statement regarding the Carioca find to decide whether to launch an inquiry.

Stock market regulator CVM said it considered the announcement "harmful" as it involved public companies and was made by a noncorporate official. It said in a statement it had asked Petrobras to clarify the case and will mull unspecified other measures in the meantime.

If confirmed, the new deep-water, sub-salt field off the coast of Sao Paulo state would be the largest find in the world in the past 30 years. [ID:nL1576374]

The ANP said the data was in the public domain after circulating in the media since February.

Petrobras, which saw its shares soar on Monday and add another 1.4 percent on Tuesday, has said more studies were required on the find without denying the estimate altogether.

Petrobras Chief Executive Jose Sergio Gabrielli told Reuters on Tuesday in Cancun, Mexico, that the oil giant was still drilling and it would likely take around three months to evaluate the size of the Carioca oil find.