Yahoo’s executive turnover: Is Bartz in trouble?

Hilary Schneider, Yahoo’s top U.S. media and advertising executive, is reportedly leaving the company, as are David Ko and Jimmy Pitaro, two executives working under her, according to AllThingsD.

The departures raise questions about the leadership of CEO Carol Bartz (pictured), a tough-talking leader who was hired to bring order to the company and slam closed what seemed like a revolving door in the Internet-media company’s executive suite.

Since Bartz was hired as Yahoo’s CEO in early 2009, she has refocused the company around its media properties, striking a deal with Microsoft to run Yahoo’s Web search and shutting down underperforming products.

But Yahoo shares have barely moved since then. Which raises the question: Is Bartz Yahoo’s ultimate underperformer?

The Yahoo CEO has another 18 months on her contract. But if she’s not able to swiftly replace Schneider and other defectors with executives who give Wall Street confidence, the board could well move to cut things short.