* Proceeds to pay debts of parent Del Monte Pacific * IPO is set to be launched in the third quarter-source * Philippines gears up for blockbuster year of IPOs (Recasts with details on IPO, quotes) MANILA, April 28 (Reuters) - Del Monte Philippines Inc filed for an IPO that could raise up to 44.1 billion pesos ($910 million), marking potentially the second-largest share offering in a market that is gearing up for a blockbuster year for listings. Del Monte’s shareholders Del Monte Pacific and SEA Diner, are seeking to sell up to 804.23 million shares, including an over-allotment option of 15%, it said in a registration statement filed with the corporate regulator on Wednesday.