Shares of Ameresco retreated after the company said its chief financial officer is leaving and reiterated revenue guidance that's a touch weaker than Wall Street estimates.

The stock was down 11% at $22.50 on Thursday. Shares have now fallen 23% year-to-date.

The energy infrastructure company said after yesterday's closing bell that Mark Chiplock has resigned as chief financial officer and will leave on Sept. 25. Chiplock has accepted a CFO position at a private equity-owned company in a different industry. The company has initiated a search to find Chiplock's successor.

Ameresco reiterate its full-year guidance, which currently contemplates $2 billion to $2.2 billion in revenue. The midpoint of $2.1 billion is slightly lower than the $2.13 billion consensus estimate of analysts polled by FactSet.