* Lead director Cox named CEO on interim basis
* Search already on for permanent replacement
* Darbee leaves after a challenging year for PG&E
NEW YORK, April 21 (Reuters) - PG&E Corp (PCG.N) said on Thursday Chief Executive Peter Darbee will retire from the company at the end of the month and will be succeeded on an interim basis by the California utility's lead director, Lee Cox.
The change comes after a PG&E natural gas line exploded in a San Francisco suburb last September, killing eight people and destroying 37 homes.
Earlier this month, the company's Pacific Gas and Electric utility also asked for a delay in processing of an application to extend the life of its two-unit Diablo Canyon nuclear plant on the quake-prone California coast to allow completion of a seismic study.
"Peter concluded that a change in leadership would create the best opportunity for PG&E to move ahead after a challenging year," Cox said in a statement.
Darbee joined PG&E in 1999 as chief financial officer and was appointed CEO in 2005. He assumed the additional role of chairman of the board in 2006.
The San Francisco-based utility said Cox will serve as chairman, CEO and president on an interim basis. A search for Darbee's replacement is under way and an announcement is expected soon. (Reporting by Paritosh Bansal; Editing by Steve Orlosky)