Amazon Web Services has prevailed in its lawsuit against the government over a cloud computing contract with the CIA, but competitor IBM has vowed to appeal the decision.

The two companies have been sparring over the high-profile contract, which was first awarded to Amazon. ( founder and chief executive Jeffrey P. Bezos owns The Washington Post and Capital Business.)

IBM protested the award to the Government Accountability Office, which found merit in the complaint and recommended the CIA reopen the competition. Amazon Web Services then took the battle to the U.S. Court of Federal Claims.

Judge Thomas C. Wheeler granted Amazon’s motion and restored the original contract in a ruling last week. The CIA “and AWS may immediately resume performance of the [commercial cloud services] contract,” the judge wrote.

Amazon said in a statement that it looks “forward to resuming our work on this important contract,” but IBM said in its own statement that it plans to appeal.

“This court decision seems especially inappropriate in light of the current times, since IBM’s bid was superior in many ways, including being substantially more cost-effective,” the company added.

The CIA said in a statement that it’s “pleased that it can now move forward with procuring critical cloud services for the intelligence community.”

CACI buys Six3 Systems

Arlington-based CACI International said last week that it has agreed to buy McLean-based Six3 Systems from private equity firm GTCR for $820 million to boost its cyber and intelligence work.

Six3 employs about 1,600 and its revenue for the year is expected to be about $470 million, CACI said. The acquisition is the largest in CACI’s history of 57 deals, said Ken Asbury , the company’s chief executive.

“We’re taking the long-term view of where the market’s going to go,” Asbury said in an interview last week. “We think that the market’s shifting to capable companies that are affordable.”

He said Six3 will become a business group within CACI and retain its name and its leadership team. “We sort of don’t want to mess with their success,” he said.

Astrophysics opens Crystal City office

Astrophysics, which supplies X-ray inspection systems, said last week it has opened an office in Crystal City to better reach its government customers. The company’s headquarters is in the City of Industry, Calif.

The office is to be led by Mark Laustra , who previously led government sales at Smiths Detection, the company said in its announcement. The 140-employee Astrophysics also has a facility in Ontario, Calif.

GAO denies SoBran protest

The GAO has denied a protest filed by Fairfax-based SoBran against a Social Security Administration contract awarded to Silver Spring-based Financial & Realty Services for warehouse support services.

SoBran, the incumbent, had argued that its past performance was not rated highly enough. The company had earned a “very good” rating while FRS earned “neutral,” but SoBran priced its proposal at $5.7 million, higher than the FRS price of just under $5.3 million.

The GAO noted that the “contracting officer then determined that the protester’s superior performance was not worth the $425,000 price differential” and backed the agency.