Running a global structured credit operation these days is tough work. Just ask Matt Zola, who resigned today as global head of structured credit at Morgan Stanley (MS), according to a report by Bloomberg News on Tuesday morning. Zola left for unidentified personal reasons, and will be replaced by New York-based Brian Neer, according to a Morgan Stanley representative. Neer was previously a managing director at the firm, and head of Asia and North America structured credit products. Zola had been at Morgan Stanley for some time, and was named to the global post in January, Bloomberg reported. Morgan Stanley earned $1.55 billion during the recently-completed first quarter, led by record revenues in equity sales and trading. Earnings came despite total write-downs for the quarter of $2.3 billion, including $1.2 billion in net MBS and related securities write-downs and another $1.1 billion in mark-to-market activity on loans. Disclosure: The author held no positions in MS when this story was originally published. HW reporters and writers follow a strict disclosure policy, the first in the mortgage trade.