HK shares hit 2-wk low as China Mobile,HSBC falter

* China Mobile drops after disappointing November data

* HSBC slides further as S&P outlook downgrade weighs

* Taiwan firms buck trend on China's support pledge

* Turnover dries up ahead of truncated trading week

(Updates to close)

By Parvathy Ullatil

HONG KONG, Dec 22 (Reuters) - Hong Kong shares fell 3.3 percent on Monday in wafer-thin volumes, with declining stocks beating advancers two to one, as investors locked in gains on a two-week rally but Taiwan companies outperformed on China's promise of help.

Index heavyweight China Mobile (0941.HK) slid more than 5.5 percent after the world's largest wireless carrier reported a 4.5 percent drop in net additional subscribers in November, its lowest numbers this year.

Also piling pressure on the main index, HSBC (0005.HK) slid 3.3 after S&P cut its outlook on the stock to negative.

"The rights issue announcement from DBS today has added to worries about fund-raising at HSBC and also dragged down some of the other locally listed banks," said Alex Wong, director at Ample Finance Group.

Singapore's DBS Group (DBSM.SI) said on Monday it planned to raise $2.74 billion in a rights offering to shore up its capital.

"Overall profit taking will dominate this week, especially after Chinese shares were overbought last week. Investors are more keen on keeping their money over the long Christmas holiday," Wong said.

The benchmark Hang Seng Index .HSI ended 505.12 points lower at 14,622.39 after opening 0.3 percent higher.

But shares in some mainland-based Taiwanese companies dodged the downdraft after China pledged to help Taiwan firms tide over the global economic downturn.

Shares in athletic footwear maker Yue Yuen Industrial (0551.HK), part of the Taiwanese Pou Chen Group, surged 13.6 percent. The stock had risen more than 47 percent soon after it opened for trade.

"The gains in some of the locally listed Taiwanese firms today look like an overreaction to me," said Conita Hung, head of equity markets at Delta Asia Financial Group.