Oracle's $7.4 billion purchase of Sun Microsystems got the sign-off it needed from federal antitrust regulators today, removing a key hurdle for the two companies' merger.

Oracle said the U.S. Department of Justice approved the deal, first announced in April, and terminated the companies' waiting period under the Hart-Scott-Rodino Act.

Along with the approval by Sun's stockholders -- who gave the transaction the thumbs-up in mid-July -- today's development leaves few obstacles still to overcome.

Chief among those is approval by the European Commission.

Getting U.S. authorities to OK the deal hadn't been guaranteed. In fact, the Justice Department in June denied Oracle's request for fast-track approval, on the grounds that they needed more time to examine the deal before passing it on to other federal regulators.

Oracle's lawyers had said at the time that they had been working with the Justice Department on resolving "one narrow issue" regarding Java licensing -- but otherwise expected few delays in getting the deal approved quickly.

The future of Java had been one closely debated aspect of the merger, with many in the industry calling on Oracle to keep Java open. By replacing Sun, others have seen Oracle bringing a needed change in leadership to Java.

MySQL gets a pass

Ironically, the DoJ apparently wasn't very interested in another aspect of an Oracle/Sun merger -- database overlap. Sun's open source MySQL database isn't a direct competitor to Oracle's family of enterprise databases, but it does increase the hegemony. MySQL notes that industry stats show that together, Oracle and MySQL would account for a huge share of the database market.

Meanwhile, even as it waited for DoJ approval, Oracle continued it acquisitive ways. Last month, July 23, Oracle announced the acquisition of GoldenGate Software for an undisclosed amount. With GoldenGate Oracle will be able to offer continuous access to business-critical applications as well as high-performance data integration. One example, GoldenGate's technology makes it less complicated to maintain application uptime during migrations and upgrades.

GoldenGate also provides real-time data warehousing and change data capture, live reporting and transactional data integration, rolled into enterprise solutions for business intelligence and service-oriented architectures -- key application areas in which Oracle plays.

InternetNews.com West Coast Bureau Chief David Needle contributed to this article.