CARIBOU – ATX, a leading software provider to accounting firms and tax preparers, is going through yet another growth spurt.

ATX announces “its largest employee growth in company history,” proclaimed a press release received Friday.

The company presently has 155 employees at its Caribou facility. Three years ago, the company had 50 to 60 employees at Caribou.

The company also has 80 employees at a Florida site and 30 in Washington, D.C.

The hiring of new employees coincides with the company’s launching of Total Accounting Office and Total Engagement Office software to its product line.

The company will be adding about 70 full-time seasonal positions to its work force at its Sweden Street business in the coming weeks.

Along with those positions, 12 to 20 new full-time software programmers and Web development and quality assurance representatives will be added, according to Bill Grady, an ATX media representative.

Seventy of the positions will be for technical support positions to assist current support staff of 80 people. They will handle the bulk of calls received during the December to April 15 tax season.

The positions, to be filled this month, will allow for weeks of training before the start of the season.

“This will make us considerably bigger than we have ever been during tax season,” Grady said Friday afternoon. “This will make our call center full.

“It’s a nice thing, and we are certainly growing all the time,” Grady said. “Our customer base continues to grow, and we are now the largest in our industry.”

He said the industry has about 50 competitors.

Grady said the positions, which begin as seasonal, full-time employment, have the opportunity of becoming permanent full-time positions after the tax season.

ATX, a company founded by brothers Steve and Glynn Willett in 1992, produces tax accounting software for more than 35,000 companies nationwide.

The company was sold to United Communications Group of Rockville, Md., a business-to-business information publishing company just outside of Washington, D.C., a year ago.

Glynn Willett remained with the company as CEO.

“These new additions will allow ATX to take yet another step towards creating a product superior to our competitors,” Willett said in a press release through Grady. “We can back our product with an unprecedented technical support staff.”

Despite the sale of the company, ATX has remained in Caribou.

ATX has been named to the Inc. Magazine Inc. 500 list of the fastest-growing private companies for each of the past four years.