Goldman Sachs named Pete Lyon as the new co-head of the investment-banking unit that covers private equity firms, succeeding Milton Berlinski, a 26-year Goldman veteran. The firm announced the retirement of Mr. Berlinski, who had run the unit alongside Alison Mass. Mr. Lyon has been with Goldman Sachs since 1990 and, for much of that time, has worked with private equity clients of the firm.  Earlier in his career, he worked in a group that provided loans to finance private equity firms’ acquisitions.  He spent much of the last decade covering some of the firm’s most important private equity relationships during the leveraged buyout boom, and then did a short stint in Dubai covering clients in the Middle East and North Africa.  [Dealbook 12/15/11]