HONG KONG, Sept 3 (Reuters) - Hong Kong's benchmark index made its largest daily gain in 9-1/2 months on Wednesday to close at its highest level since May 2008, while China's onshore markets took heart from upbeat results of two surveys on service sector activity.
The services purchasing managers' index (PMI) compiled by HSBC/Markit jumped to 54.1 in August - the strongest in 17 months - from a nine-year low of 50.0 in July, while the official non-manufacturing PMI rose to 54.4 from July's six-month low.
The Hang Seng Index climbed 2.3 percent to close at 25,317.95 points. The China Enterprises Index of leading offshore Chinese listings in Hong Kong was up 3.2 percent, its highest close since December 10.
Wednesday was the best day for both indexes since November 18, with gains coming in the strongest volume since April 10.
Henderson Land led gainers on the Hang Seng, jumping 6.2 percent to it highest in 6-1/2 years. Stock exchange filings showed the developer's chairman Lee Shau-kee raised his holding in the company during the past few days.
Chinese state banks lent the strongest support to the H-share index. Industrial and Commercial Bank of China spiked 4.6 percent and China Construction Bank rose 4.1 percent, their best daily gains in more than a year.
Reporting by Grace Li; Editing by Simon Cameron-Moore