Industry advisers say the trend is likely to continue as companies become more confident about government budgets.

"In 2013, there was a lot of confusion about sequestration -- what that meant for spending and whatnot -- and some of those questions got resolved in 2014," said Eric Fahr, managing director in BDO's transaction advisory services practice. "You saw a pick-up in activity."

Bob Kipps, managing director of the Tysons Corner, VA-based investment bank KippsDeSanto, said contractors are also in better financial health.

"There are an increasing number of businesses that are growing this year," he told InsideDefense.com. "What you're seeing is growth coming back into the industry."

In particular, Kipps noted, the Harris-Exelis deal reflects a new confidence in the government market. Harris has both government and commercial work; its acquisition of Exelis would beef up its federal business.

"It's really the first big bet on stability and resurgence of the government market," he said. "That was a real telling deal in my mind."

In a call with analysts earlier this month, Harris chief executive William Brown called the deal's timing "excellent."

"The U.S. government spending cycle has bottomed and recent world events only stress the importance of defense and national security spending," he said.

ManTech International executives said in a recent earnings call that the improving environment is encouraging them to focus on acquisitions.

"There's more certainty around budgets, we have greater clarity around the prioritization of those budgets," Kevin Phillips, the contractor's chief financial officer, said in a call with analysts. "We believe it's a good time for us to focus on acquisition."

George Pedersen, ManTech's chief executive, said in the same call that the company is "in a strong position to make more acquisitions to grow the company."

In 2014, ManTech bought 7Delta, a company specializing in application and software development, information assurance and security architecture services for the Department of Veterans Affairs, as well as Allied Technology Group, an engineering and information management contractor focused on the Department of Homeland Security.

ManTech isn't the only contractor that has publicly said it is on the hunt. NCI recently bought Computech, a company that works with federal agencies including the Federal Communications Commission and the Internal Revenue Service.

Brian Clark, NCI's president, told InsideDefense.com earlier this year that he's seeking acquisitions with up to $200 million in sales. "We'll continue to be a consolidator, we'll be looking for those acquisitions," he said.

Booz Allen Hamilton last year purchased two health-related companies, and Horacio Rozanski, the contractor's chief executive, told InsideDefense.com the company could act on more.

"When the right acquisitions present themselves, we will take action," he said. "The reality is that we sit in a position of strength, so we're going to make acquisitions that make sense for our business."

Eric Sobota, partner in charge of BDO's government contracts and grants advisory services business, said he expects a mix of acquisitions. Some contractors will pursue companies with specialties in certain areas, like health IT or cybersecurity, while others will move to increase their size through consolidation.

"I would expect more of both at the end of the day," he told InsideDefense.com. "The smaller, niche companies are good targets . . . but there's a lot of benefits to consolidation on a global level."

In general, he added, consolidation provides "a substantial savings" that can "translate into a competitive edge."

Yet some of the most recent buyers say they're taking a break. Vencore, for instance, last year purchased QinetiQ North America's services and solutions group.

Mac Curtis, Vencore's chief executive, told InsideDefense.com this month that the company is "still digesting."

"Let's let the dust settle," he said. "But we're also opportunistic, so if there's something that makes sense . . . we'll take a look at it."

Tony Smeraglinolo, chief executive of Engility, which finalized its purchase of TASC this week, said his company too is focused on integrating its acquisition -- but will also remain open to new opportunities.

"I think consolidation will beget more consolidation," he told InsideDefense.com "When they see two great companies come together to form a $2.5 billion entity, how do you compete against that?" -- Marjorie Censer

INSIDE DEFENSE — InsideDefense.com