BRASILIA - A Brazilian prosecutor said on Monday that new information turned up in the Petrobras corruption scandal that could lead to the annulment of the state-owned oil company’s purchase of Pasadena Refining Systems Inc in Texas in 2006. Brazil’s Federal Police on Monday began a new round of arrests and searches for evidence in the case that include seven former officials at Petroleo Brasileiro, as Petrobras is formally known, who are under investigation over alleged graft related to contracts for the company’s Pasadena and Abreu e Lima refineries.