Local government and University officials responded enthusiastically to the announcement by Pfizer, Inc. that the world's largest pharmaceutical company is expanding its Ann Arbor property.

Pfizer paid $19.6 million for 29 acres of land near North Campus from the non-profit research company Altarum Monday. The purchase is adjacent to the 144 acres already owned by Pfizer, part of which was acquired from the University in September.

With 3,600 employees working at its Ann Arbor Laboratories, the New York-based Pfizer is Ann Arbor's largest private employer. The company makes drugs such as Viagra, Zoloft and Lipitor.

University Chief Financial Officer Robert Kasdin said the expanding site contributes to the University's research opportunities.

"It's a matter of forming a critical mass of researchers, both at the University and in the private sector, who through formal and informal contact, enhance research," he said. "This is another movement in that direction."

Kasdin said the University and Pfizer have not discussed the possibility of making another land sale.

The two parties work together on many projects, Pfizer spokeswoman Betsy Raymond said, adding she anticipates further cooperation with the University as the Life Sciences Initiative takes shape.

"There are research relationships already, and have been for years, between the University and the laboratories," she said.

Ann Arbor Mayor John Hieftje said Pfizer's expansion shows the drugmaker's continuing commitment to Ann Arbor.

"I think Pfizer is here for the long term," he said. "This is another example of this - another example of the fact that we made the right decision when we decided to work with them on their taxes last year. We've cemented their place in the community."

The City Council granted Pfizer a 50 percent tax abatement on the former University property in October. The grant came with several stipulations for the company including a minimum investment in its property and an agreement to help the council deal with housing and traffic issues.

The new acquisition is not eligible for an abatement, according to city officials, and Raymond said the company has no plans to seek one. Pfizer Ann Arbor Laboratories paid $7.3 million in state and local taxes last year.

More employment opportunities will enter the area as Pfizer expands, said Tim Robinson, vice-president of operations for the Washtenaw Development Council.

"These are very well-paying jobs," he said. "That's more money that gets recycled in the community. ... Usually it can lead to a greater quality of life for the county."

Raymond agreed the expansion will lead to job growth but said its greatest effects will not take place immediately. Pfizer is planning 20 to 30 years in the future with the acquisition, she said.

"Pfizer is buying land now to be prepared for future expansion," she explained.

Ann Arbor's growing importance gives the city a voice in the direction of that expansion, Raymond said.

"When the Pfizer research division plans what it needs ... Ann Arbor can now participate in that planning," she said.