I was not sure how common this pattern was. I asked a language exchange partner about it and he said that it is basically a very formal version of 때문에. It is ost commonly seen in written and formal works such as news articles and broadcasts.

• 기차가 늦게 오는 관계로 늦게 도착했어요.
• 우산이 없는 관계로 옷이 젖었어요.
• 비용이 많은 드는관계로 저금을 못 들었어요.