HONG KONG, May 17 (Reuters) - China needs to be more aggressive in its reforms if it wants to smoothly transition from an export-oriented economy to a services-driven one, the head of BlackRock Inc., the world's biggest asset manager, said on Tuesday.

"China is struggling with excessive leverage within a lot of financial institutions," BlackRock Chairman and Chief Executive Officer Larry Fink said at a BlackRock forum in Hong Kong.

"They need to be more aggressive in their reforms. Reforms are slower than what I would have preferred."

He added there are still too many state-owned enterprises in China and that the recent "explosion in credit" is "the wrong way to reorient the economy".

(Reporting by Lisa Jucca; Editing by Sam Holmes)