Idexx has announced plans for a $100 million expansion at its Westbrook plant that would bring 500 more jobs to the area. In exchange, the company is asking for tax breaks from the city and state.

Idexx Chief Executive Officer Jonathan Ayers said the company signed a purchase and sale agreement last week for the building it now leases in the Five Star Industrial Park on Eisenhower Drive.

“We’re moving from a tenant to a homeowner,” Ayers said. He did not disclose the exact terms of the sale, though he estimated the cost to purchase and renovate the existing building at $40 million.

Idexx purchased the building from its landlord, S.R. Weiner, a Massachusetts retail development company that formerly owned the Maine Mall and has developed the Kohl’s and Shaw’s shopping plaza in Westbrook as well as shopping centers in South Portland, Freeport, Biddeford, Brunswick, Augusta and all throughout New England.

Idexx occupies 350,000 square feet in its building now. The company will add to that space by moving into a 130,000-square-foot space previously occupied by Sanmina SCI in the same building. The space became available after Sanmina announced in 2004 it was closing its Westbrook operations. Idexx plans to dedicate the new space to manufacturing, research and development labs and office space.

Additionally, the company has signed a seven-year lease for a 55,000-square-foot building in the nearby Colonel Westbrook Industrial Park on Spring Street. Idexx Vice President of Worldwide Operations Laurel LaBauve said space would be used as a training center for new employees as well as a customer service call center.

Idexx Laboratories is an international company that develops and manufactures diagnostic, detection and information systems for veterinary, dairy and water testing.

Idexx, which has 40 locations in North America, Europe, Asia and Australia, does the bulk of its research and development in Maine. In 2004, it developed a test for mad cow disease that is used throughout Europe, and Gov. John Baldacci recently named the company Maine Exporter of the Year.

After hearing the news last week that Idexx would be staying in the area, employees were happy to know the company planned to remain in the city. Chris Lewis, a finance manager who has been with Idexx for eight years, said he was glad to hear the news.

“I think it’s great,” said Lewis. “I am a Maine guy, and from my perspective, this cements Idexx’s commitment to Maine.”

Idexx’s plans stretch beyond the buildings it is occupying on Eisenhower Drive and off Spring Street. Ayers said the company also owns a 12-acre plot of land directly across the street from its headquarters. He said the company’s future plans for that land, which it purchased in 1997 for $275,000, include potentially building a 150,000-square-foot office building on that site, though he did not have a timetable as to when construction would begin on that project.

In order to ensure Idexx remains in Westbrook, the city is looking to provide the company with a tax break to help it pay for the expansion. Under the 20-year tax increment financing agreement, which still needs to be approved by the City Council, the city will return two-thirds of all property taxes generated from the new investment.

Idexx estimates that its investment will generate approximately $15 million in new taxes over the life of the agreement. Under the terms of the proposed agreement, this means the city would receive $5 million in new taxes and return $10 million to the company.

Besides the proposed municipal tax break, Idexx will be receiving tax breaks from the state. Westbrook Director of Economic and Community Development Erik Carson said the state and Idexx are still working out the details of the tax breaks.

Carson said the state would likely be providing what is known as an employment tax increment financing agreement. Under that agreement, the state will refund a percentage of the company’s state taxes if the company creates at least 15 new full-time jobs.

“Obviously, they’re going way beyond that,” said Carson.

Carson said other tax breaks being discussed by the state and Idexx include a jobs and investment tax credit, where the state gives a tax break to allow the company to purchase new equipment. Carson said this tax break is based on the creation of at least 100 new jobs, which is well under the 500 new jobs Idexx is proposing to add.

The state is also likely to allow Idexx to tap into a program designed to provide money for employee training. Carson said the program gives companies $800 for every new employee hired, with the money earmarked for employee training and retention programs.

State Rep. Tim Driscoll said the news of Idexx’s expansion is a shot in the arm, not just for Westbrook, but also for the entire state. “Maine’s new economy is beginning right here in Westbrook,” said Driscoll. “This expansion means that good-paying technical and professional jobs will allow our children to stay and work in Maine.”

The tax break was a significant factor behind Idexx’s decision to stay in Westbrook. Because Idexx is a publicly traded company, Ayers said the company has to make sure it is getting the best deal possible for its shareholders.

“We have an obligation to our shareholders to be competitive,” Ayers said.

Baldacci said Idexx’s decision to stay in Westbrook benefited all of Maine. “It’s a great day in the state of Maine,” he said. “It reflects well on all of us and what we’re doing to attract new jobs and businesses here.

The 500 new jobs created by the Idexx expansion will be good ones, Ayers said. He estimated the median salary at the company was $50,000, which is 50 percent higher than the state average.

The quality of the workforce in the area was a big selling point to Idexx and Ayers said the jobs created by the company’s expansion would create more opportunities for Mainers. “The workforce we have in Maine is second to none,” he said.

Jack Cashman, commissioner of the state’s department of economic and community development, agreed that Maine’s workforce was a selling point. “People in Maine know how to work for a living,” he said. “The best thing we have going for us is the work force.”

Assistant House Majority Leader Robert Duplessie said he hopes more companies like Idexx will recognize the quality of Maine’s workers and relocate here. “As we create more opportunities for biomedical research and development, we will ensure that companies like Idexx have the human resources available to grow,” Duplessie said. “There is no better work ethic in this country than the people of Maine, and we must continue to ensure that we move with the pace of information and technology.”

Ayers said while he realizes there is some risk in making such a large investment, he is looking forward to Idexx continuing to grow and prosper here. “We’re very excited about making this commitment,” he said. “We feel very good about our future here.”

Lewis said he has found Idexx to be a great place to work. “It’s a good company,” he said. “There are a lot of great people here, a lot of good Maine talent. Everyone takes their job seriously and they’re great at it.”