Aug 18 (Reuters) - Calpine Corp CPN.N
* Canada Pension Plan Investment Board signs agreement to acquire stake in Calpine Corporation
* canada Pension Plan Investment board says CPPIB will invest US$750 million in relation to Calpine deal
Aug 18 (Reuters) - Calpine Corp CPN.N
* Canada Pension Plan Investment Board signs agreement to acquire stake in Calpine Corporation
* canada Pension Plan Investment board says CPPIB will invest US$750 million in relation to Calpine deal