UPDATE 1-Brazil's Bolsonaro backs Economy Minister Guedes, an 'anchor' in his government

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BRASILIA, Feb 24 (Reuters) - Brazilian President Jair Bolsonaro said on Wednesday that Economy Minister Paulo Guedes is an "anchor" in his government, seeking to quash speculation of a deepening division between the two after he moved last week to oust the chief executive of state-run oil giant Petrobras.

Guedes, a Chicago-school trained economist and fervent free-market supporter, has not commented on Bolsonaro's intervention at the top of Petrobras, which unnerved investors and sparked a huge selloff across Brazil's financial markets on Monday.

"Paulo Guedes is an anchor for our government," Bolsonaro said at a ceremony in Brasilia marking the signing into law of central bank autonomy.

Addressing Guedes alongside him on the stage, Bolsonaro said his commitment to fiscal discipline sends a positive signal to financial markets.

Earlier on Wednesday, ratings agency Moody's warned that Bolsonaro's decision to replace Petrobras chief executive Roberto Castello Branco over rising fuel prices threatened the government's privatization program and even Brazil's economic growth.

A survey of 200 institutional investors carried out by online brokerage XP Investimentos on Sunday, after Bolsonaro's Petrobras intervention, showed that a growing number think Guedes will not hold his position as economy minister after June.

The survey showed that only 13% of those polled think Guedes will definitely be in his position come the second half of the year, with the remainder attaching various probabilities to him leaving.

Almost half (49%) estimated there was a 0-25% chance of him being gone by June, almost a quarter (23%) estimated there was a 25-50% chance, and 13% attached a 50-75% probability, the survey showed. (Reporting by Ricardo Brito and Jamie McGeever Writing by Jamie McGeever Editing by Leslie Adler and Aurora Ellis)