CEBU, Philippines Sept 10 (Reuters) - Asia-Pacific nations must integrate their financial markets more closely to boost trade and investment, the Philippines' national treasurer told a meeting of finance ministry officials from the Asia-Pacific Economic Cooperation (APEC) group on Thursday.

"It is imperative for APEC to further advance financial integration as a driver for intensified intra-regional trade and investment," National Treasurer Roberto Tan said, even as China's slowdown clouds economic prospects.

Tan was speaking at the start of a meeting of finance ministers from the 21-member bloc on the Philippine resort island of Cebu.

He also called for fiscal reforms to make policy more effective, and stressed the importance of public-private partnerships in financing the region's infrastructure needs, estimated by the Asian Development Bank at $800 billion a year.

"For this to materialise, bankable projects have to be identified in the pipeline and capital markets developed," he said.

The Cebu meeting takes place amid growing concern over slower growth in China, the world's second-largest economy, and recent ructions in global financial markets following Beijing's devaluation of its yuan currency last month.

APEC's members include the United States, China, Japan, South Korea, Indonesia and Canada, and together account for 57 percent of global production and 46.5 percent of world trade.

In public, delegates have refrained from expressing concerns about China, but one source at the closed-door talks said a lack of financial market integration was partly to blame for recent market swings.

"If China adhered to market forces it should have adjusted more gradually," he said, asking not to be identified because of the sensitivity of the issue.

Coming only days after a meeting of finance ministers from the world's 20 largest economies in Ankara, Turkey, the APEC talks risk being overshadowed.

This year, only a handful of governments have sent ministers to represent them at the forum.

Asked if he was disappointed that so many ministers had chosen to skip the meeting, Philippine Finance Undersecretary Gil Beltran said that it was usual.

"That does not diminish our commitment to many of the initiatives that we agree on," he said.

Peru is due to host next year's APEC meetings, but its finance minister was among the no-shows.

Peruvian finance ministry official Fabier Roca Fabianis said the minister himself could not come because of political problems at home.

"This is not a measure of commitment - the presence or no presence of the ministers," Fabianis said.

(Reporting Karen Lema, Rosemarie Francisco and Nicholas Owen; Writing by Nicholas Owen; Editing by Jacqueline Wong)