Jan 15 Brazil's state-run oil company Petroleo Brasileiro SA is pressing ahead with the sale of $15 billion in assets but may need to make further cuts to its investment plan depending on oil prices, the company told analysts on Friday according to a client note from ItaAo BBA. Petrobras did not rule out help from the government but said it was not on the table right now and would be a last resort, ItaAo BBA said.