SHANGHAI, Oct 11 (Reuters) - German chemicals group BASF expects its sales in the greater China region to grow more than 10 percent this year, as it continues expanding in mainland China to cash in on a booming economy.

BASF, which competes with Degussa, Bayer AG and other chemical makers worldwide, saw average annual sales growth of more than 10 percent in greater China over the past decade, its Asia Pacific president told Reuters on Thursday.

Sales in greater China, which includes Hong Kong and Taiwan, came to 3.6 billion euros ($5 billion) in 2006, making up nearly 50 percent of its overall sales in Asia.

"In the future, we see China's contribution will be at least that big, if not bigger," said Wolfgang Hapke, in Shanghai to unveil the firm's new automotive centre in the outskirts of the city.

BASF, the world's top chemical maker, invested about 2 billion euros in greater China from 1995 and 2005.

To help maintain its growth momentum, it is expanding a petrochemicals complex in Nanjing, along with its local partner, including a 25 percent increase in the facility's cracker capacity and an expansion of downstream capacities.

The company, which already runs 29 production sites in greater China, has also said it was planning a new diphenylmethane diisocyanate (MDI) plant in Chongqing in southwestern China.

The facility, planned for startup as early as 2010, is expected to have production capacity of 400,000 metric tonnes per year of crude MDI, an important raw material for polyurethane used in a wide range of industries including construction and automotive manufacturing.

BASF will invest 1 billion euros in Asia until 2009, with half of that going to the greater China area, Hapke added.

The German chemical giant, which last year acquired U.S. catalyst maker Engelhard for $4.8 billion, has made several acquisitions in China so far, including a catalyst producer and construction chemical businesses.

Hapke did not rule out further acquisitions in China if opportunities arose.

"Everything which would strengthen our portfolio in regard to getting either more capacity or broadening our depth in the production chain would be of interest to BASF," he said. ($1=.7068 Euro)