Sentencing has been scheduled for Tuesday and Pravin could be handed the death penalty or face a lesser penalty of life imprisonment.
Ujjwal Nikam, a prosecution counsel told reporters: "I will apply my mind to say which type of punishment should be asked for him against the heinous crime."
Pramod, regarded as a possible future head of the party, died in hospital 12 days later at the age of 56.
Police had said his younger brother Pravin had confessed to the murder but later retracted the statement in court.
The prosecution said Pravin, who did not have a steady job, was angry after Pramod refused his demand for a large sum of money.
The trial, held partly behind closed doors, saw the prosecution produce a "threatening" mobile phone text message sent to Pramod as evidence against Pravin.
The defence had then called in a telecommunications expert to show that messages on mobile phones could be tampered with.
"For the last 10 days I knew that I will be convicted," Pravin said, while his wife wept in court.