Pickering Energy Partners, a Houston-based energy financial services firm, agreed to merge with SailingStone Capital Partners, an investment firm specializing in the global natural resources sector. Financial terms were not disclosed. "We have known the SailingStone principals for many years. MacKenzie Davis and Ken Settles were among the first clients of our predecessor firm in 2004, while Brian Lively was a key contributor to the TPH energy research franchise for a number of years," Dan Pickering, Pickering Energy Partners CIO.