Shares in Linux software developer Red Hat (Nasdaq: RHAT) fell more than 6 percent Monday after the stock was downgraded by Goldman Sachs.

Analyst Rick Sherlund cut Red Hat to “underperform” from “in line”.

Red Hat shares closed at $28.51 on Monday, off from Thursday’s close of $30.55.

The stock fell a further 51 cents in after-hours trading.

The move came after Red Hat’s announcement last week to acquire open source developer JBoss.

Sherlund said the JBoss deal put Red Hat on a “collision course” with Oracle and IBM, according to Investor’s Business Daily.

Red Hat: www.redhat.com