Aug 14 (Reuters) - M&G Investments:
* M&G Investments requests initiation of strategic review process for Gibson Energy Inc.
* Says M&G currently manages funds owning approximately 19.4 percent of outstanding shares of Gibson
* Company should exit all lines of its trucking business that are not associated with core infrastructure assets of company
* Says Gibson Energy should sell Moose Jaw refinery and its affiliated lines of business and use proceeds to reduce debt
* Believe Gibson Energy should commence a strategic review of all options, including sale of co, with help of independent investment bank
* On Aug 14, delivered letter to James M. Estey, Chairman of Gibson Energy's board discussing its views, measures Gibson should take