China's top online auction firm, Taobao, recorded transaction volume of 80.9 billion yuan ($11.8 billion) in the first half of 2009, up 97% year-on-year, according to mid-year metrics released on Thursday, despite the slight drop in spending per order due to the economic slow-down.

The e-commerce company, part of Alibaba Group, which also controls Alibaba.com , said the rise in volume was due to a 101% jump in the number of registered users and the growing acceptance of e-commerce among China's Internet users.

By June 30, 2009, Taobao's registered users grew to 145 million, accounting for 43% of total Chinese netizens .

According to the report, 47% of Taobao users are between the ages of 26-35, while 39% are between the ages of 16-25.

What is most interesting is the level of mainstream acceptance of using online retail channels to shop for everyday items, said Jonathan Lu, president of Taobao.

The company said spending per order declined by RMB 51.5 ($7.54) from last year due to the economic slow-down, but the overall number of orders rose by 184% as e-commerce gained broader acceptance among China's online population.

Household goods have become the top selling category in terms of total sales transaction value for the first time, Taobao said.

Taobao, which is widely considered China's eBay, has a 78% share of China's domestic online consumer market, the firm said, quoting statistics from iResearch.