Merrill Lynch, New York, (NYSE: MER) has acquired energy investment-banking and M&A advisory firm Petrie Parkman & Co., Denver and Houston, for an undisclosed price. Co-founder Tom Petrie will become a vice chairman of Merrill Lynch and member of the executive client coverage group. Petrie Parkman is now part of the energy and power group of Merrill Lynch's global markets and investment banking group. The group has changed its name to Merrill Lynch Petrie Divestiture Advisors.