MANILA (AFX-ASIA) – Petron Corp expects to raise its pump prices by another 0.30-0.50 pesos per litre by end-April to recover higher crude costs, spokeswoman Virginia Ruivivar said. (US$1 = 50 peso).Ruivivar said Petron also plans to implement a 0.30-0.50 peso price increase by the end of this week.”If we increase the end of this…