Siemens ( SI) said its Siemens Power Generation unit is acquiring Wheelabrator Air Pollution Control from private equity firm Aquilex.

Terms weren't disclosed, but Siemens said Pittsburgh-based Wheelabrator designs and supplies air pollution reduction products for the coal-fired power and industrial markets. Sales so far this year are $116 million.

Siemens, based in Germany, said it wants to sell more market-driven solutions for cleaner, more efficient power generation infrastructure.

"The existing global coal-fired power infrastructure will continue to be a mainstay of the power industry. Efficiency and the environment are critical decision factors for our customers thereby fueling a growing global demand for pollution prevention and controls," said Siemens Power chief Randy H. Zwirn.

"With this in mind, we are committed to helping our customers address this demand by delivering a broad portfolio of highly efficient and cost-effective solutions that have a minimal impact on the environment."

On Wednesday, Siemens' shares fell $1.07 to $75.89.