This kind of clause is called a "participle clause" (specifically, a "present participle clause"). They're not easy to learn, because they express a wide variety of meanings. On the other hand, they're very nice because you can convery a lot of meaning very succinctly and cohesively. Note that they're a feature of written English and seldom come up in spoken English.
Here's a nice short article on the subject. You might want to look up 分词从句 on Baidu for more:
In the example you gave, the participial clause expresses REASON. Without with participle clause, the sentence looks like this:
"This industry is the world's leading industrial contributor, because it produces over 6 per cent of the world's gross national product."
If you want some practice, do some much research on the subject and try rewriting the following using present participle clauses.
1. I really wanted to go to Beijing, because I am from there
2. I couldn't afford the train ticket to Beijing, because I had no money
3. I found myself in Tianjin instead of Beijing, because I had fallen asleep on the train
4. I was fined 10,000 yuan, because the train official (had) found out I didn't have a ticket