MANILA -- Philippines President Rodrigo Duterte has approved for auction nine infrastructure projects worth 171.14 billion pesos ($3.58 billion), including improvements at a congested airport in the capital here.

A 75 billion peso contract to upgrade Ninoy Aquino International Airport is up for grabs. Other projects, put together by the National Economic and Development Authority (NEDA), include a 38 billion peso bus system to connect business districts and the airport along the capital's busiest highway and a 24 billion peso flood management project for Manila.

In the provinces, there is a 10-billion-peso project to boost agricultural competitiveness for small farmers; 8-billion-pesos for acquisition of coast guard vessels; a 5-billion-peso international airport in the Bicol region; and 2-billion-peso plus hospital modernization projects in both eastern and central Visayas.

NEDA, chaired by Duterte, also increased the project value of the already approved New Bohol Airport to 7.8 billion pesos.

"Once implemented and completed, these approved projects will help attain our medium- and long-term development," said Ernesto M. Pernia, the socio-economic planning secretary.

Duterte's government has also modified the rules governing approval of infrastructure projects, giving greater autonomy to agencies, and reducing the number of cabinet ministers on the NEDA board.

Duterte is the first Philippine president from Mindanao in the south, and has promised more provincial economic development and inclusivity. He plans to ramp up infrastructure spending to 4.4% of gross domestic product next year, in line with a target to reach a 5.8% infrastructure-to-GDP ratio by 2018.

Duterte's predecessor, President Benigno Aquino, awarded 12 public-private partnership infrastructure projects totaling 223 billion pesos during his six-year term, but encountered delays with both approvals and implementation.

Among the major companies that participated in major infrastructure auctions under Aquino were Ayala Corp., Metro Pacific Investments, San Miguel Corp., DMCI Holdings Inc. and JG Summit Holdings.