Shares of Red Hat fell 10.6 percent in after-hours trading today as the company's fourth-quarter forecast disappointed investors.

Red Hat's fourth-quarter projection of $614 million to $622 million in revenues means sales will be just about flat quarter-to-quarter. Revenues for the company's third quarter, which ended Nov. 30, were $615 million.

Investors expected third-quarter revenues closer to $622 million and fourth-quarter sales of $638 million, Investors Business Daily reported.

Part of what's happening is that Red Hat is scoring larger deals. But the downside is that fewer customers are paying upfront, CEO Jim Whitehurst said on today's conference call with analysts.

The company also had some "sizable" deals with the U.S. government that were delayed, Whitehurst said— although that doesn't help to explain the apparent weakness in the fourth quarter.

Of course, Red Hat isn't ignoring the glass-half-full side of all this, namely: larger deals. In fiscal 2017 so far, the company has closed 73 deals of more than $1 million, up 40 percent compared with the first three quarters of fiscal 2016.

Those large deals included "several" OpenStack deals during the third quarter, as well as two large deals for OpenShift, the company's Docker-based platform-as-a-service (PaaS), Whitehurst said. The two OpenShift deals were worth more than $5 million and $10 million, respectively.

Red Hat also announced that CFO Frank Calderoni will leave in late January to become CEO at another company. Calderoni was CFO at Cisco for seven years before leaving in 2015 to join Red Hat.

Eric Shander, the company's vice president of finance and accounting, is slated to replace Calderoni.

Red Hat's third-quarter revenues of $615 million were up from $524 million in the same quarter a year ago.

Third-quarter net income was $68 million, or 37 cents per share, compared with the previous year's $47 million, or 25 cents per share.