The board of directors of the Pennsylvania Convention Center Authority elected Gregory J. Fox as its new board chairman on Friday, following the abrupt resignation of Thomas "Buck" Riley the preceding week. Fox, a partner at Philadelphia's Montgomery, McCracken, Walker & Rhoads LLP, originally was appointed to the board in 2002. The $786 million expansion of the Pennsylvania Convention Center debuted in March, and the venue has hosted several large shows since then. The reasons for Riley's departure were not disclosed.