Protection One is back on tech’s version of the Big Board.

Lawrence-based Protection One Inc. on Monday closed its merger with Integrated Alarm Services Group, an Albany, N.Y.-based company that also provides monitored security services.

The combined company – still called Protection One and still based at 1035 N. Third St., in the I-70 Business Center – now has about 3,100 employees, combined revenues of about $365 million and plans for annual net savings of $11 million to $13 million.

Its shares also are back on the Nasdaq Global Market, three years after being delisted from the New York Stock Exchange because of mounting debt and other issues.

Now – since affiliates of Quadrangle Group LLC bought the struggling company in 2004, moved it from Topeka to Lawrence a year later and worked aggressively to restructure its debt – Protection One is back out in the market, looking for growth options and building on its pre-merger base of about 1 million customers.

“We are confident that we : can execute our plan to take the combined company forward and reach new levels of success,” said Richard Ginsburg, Protection One’s president and chief executive officer.

Protection One’s new trading symbol is PONE, instead of the PONN ticker it had been using on Nasdaq’s over-the-counter bulletin board. Protection One had been on Nasdaq’s main market from 1994 to November 1998, when its shares shifted to the New York Stock Exchange and remained until December 2003.

The return to Nasdaq’s major market will be expected to boost the company’s visibility – it is the only Lawrence-based company to have its shares traded on a major national market – and provide liquidity for shareholders.

Protection One shares closed Monday at $13.90, the day’s opening price. Protection One shares had closed Friday at $19.85, while Integrated Alarm shares had closed at $3.84.

Upon completion of the merger, owners of Integrated Alarm received 0.29 common share of Protection One for each full share of Integrated Alarm.

Darius Nevin, Protection One’s chief financial officer, said that the Lawrence headquarters – now with about 70 employees – would be expected to add about another 30 jobs during the next year, mostly in accounting, financial services and human resources. Jobs also will be added at a monitoring center in Wichita, which has about 500 employees.