Aquino will take a delegation of about 100 top Filipino businessmen with him for the four-day trip, which begins on Sunday, to help boost Japanese interest in the country, said Board of Investments chief Cristino Panlilio.

"We expect him to bring (home) at least one billion dollars in investments from Japan," Panlilio told AFP.

He said energy, ship building, mining and property development were some of the sectors expected to see confirmed new Japanese investment.

Japan is already the Philippines top trading partner, with bilateral trade reaching $14.5 billion last year, according to government data.

Japanese companies directly invested 58.3 billion pesos ($1.3 billion) in the Philippines last year, according to the official figures.

Aquino, who came to power last year, has made attracting foreign investment one of his top economic priorities, with the Philippines lagging other Southeast Asian countries due to corruption, red tape and poor infrastructure.

During a trip to China last month, Aquino secured commitments for $1.28 billion of investment, the government said.

Japan's ambassador to the Philippines, Toshinao Urabe, said this week Japanese businessmen were eager to see if Aquino could improve the nation's investment environment.

Urabe cited the Philippines' vast natural resources and its large, English-speaking workforce as assets, but said poor infrastructure and high energy costs continued to keep investors away.

"There is huge potential (but) if you look at the statistics, investment is growing in other (Southeast Asian) countries but not so in the Philippines," he told reporters.