By Marta Nogueira
RIO DE JANEIRO, Feb 20 (Reuters) - Brazil is gauging marketinterest in exploring for oil and gas in the country beforedeciding whether to go ahead with a new auction of blocks in thefirst half of this year, the Energy Ministry said on Friday.
The 13th oil rights auction, Brazil's first sale of oil andgas concession rights since 2013, is currently scheduled forbetween late April and mid-May, according to oil regulator ANP.
But a corruption scandal engulfing state-run oil giantPetroleo Brasileiro SA and the recent plunge in oilprices have raised the possibility that the auction will have tobe put off until the second half of 2015.
The widening corruption investigation has deepenedPetrobras' financial woes and struck some of its main suppliers.
The Energy Ministry said a decision is still in the works,though time is running out.
"For the moment, we are studying market conditions and thesituation of the companies that supply goods and services in thecountry," the ministry said in a statement emailed to Reuters.
It said a decision on which blocks will be auctioned must bemade before the end of February if the auction is to happen byJune.
Executives from some of Brazil's largest construction andengineering firms have been arrested for allegedly skimmingbillions of dollars off contracts with Petrobras.
Uncertainty over Petrobras' future and its capacity toinvest in the exploration of new oil fields has raised doubtsabout the auction, said Alexandre Calmon, an oil industry lawyerand partner at Veirano Advogados law firm in Rio de Janeiro.
"Petrobras' problem is financial. If it is in financialtrouble, how can the government go ahead with the auction?" hesaid.
The lack of definition on the auction has pushed oilcompanies to look at prospects in other countries with greaterinterest, Calmon said.
The 13th oil rights auction is expected to offer areas inBrazil's promising Eastern Margin offshore region, but would notinclude any of the so-called "subsalt" resources. (Reporting by Anthony Boadle; Editing by Leslie Adler)