Currently located in 56,000 sf in Cambridge, the company, which manufactures fuel cells, will move its administrative offices along with its manufacturing and research operations into 110,864 sf at 129 Concord St. in Billerica in June, 2007, under a 12-year lease signed last month with New Boston Fund. New Boston owns the Rivertech Office Park building. Terms of that lease were not disclosed, but office rates in the Route 128 market, which includes Billerica, averages $21.66 per sf, according to a study prepared by Richard Barry Joyce and Partners.

Company officials say the expansion represents a projected staff expansion of 250 employees over the next five years. The company presently has 100 employees.

Funding for the renovation work was provided in part by Mass Development, which secured a seven-year, $5.8-million loan consisting of a $2.5-million Emerging Technology Fund loan and a funding commitment of $3.3 million from the Massachusetts Technology Collaborative. The town of Billerica also approved a 20-year Tax Increment Financing agreement that gave the firm more than $410,000 in tax savings.