Adds company comment, details of transaction, share price

Feb 20 (Reuters) - German engineering company Siemens SIEGn.DE has raised roughly 1.45 billion euros ($1.5 billion) after selling a stake in healthcare subsidiary Siemens Healthineers SHLG.DE, with proceeds expected to help pay for its acquisition of U.S. software firm Altair Engineering.

The company sold a 2% stake, or 26.5 million ordinary shares, via a private placement, it said late on Wednesday, reducing its stake in the medical equipment maker to 73% from 75%.

CEO Roland Busch has said that Siemens would likely reduce its stake in Healthineers by around 5% this year, and also offload 6% of its holding in Siemens Energy ENR1n.DE.

Strong investor appetite allowed Siemens to increase the transaction size from 22 million shares initially. The company said proceeds will be used for "general corporate purposes."

A Siemens spokesperson said the company had previously communicated that proceeds would help to finance the acquisition of Altair Engineering.

Last year's $10.6 billion acquisition of Altair was the second biggest in the company's history.

"This intention has not changed," the spokesperson said.

Siemens has agreed to a lockup period where it will not sell more of its remaining 823.5 million shares for 90 calendar days.

Shares in Siemens Healthineers fell in early trading.

Morgan Stanley, Barclays, and BNP Paribas acted as global coordinators and book runners for the sale, which will be completed on February 24.

Siemens also recently reduced its holding in Siemens Energy from 15% to 14.3%, and has said it will gradually reduce this further during 2025.

The company intends to provide a strategic update on Siemens Healthineers to investors in December this year, CFO Ralf Thomas told analysts last week.

($1 = 0.9610 euros)

(Reporting by John Revill,Andrey Sychev and Urvi Dugar; Editing by Emelia Sithole-Matarise and Stephen Coates and Rachna Uppal)

((john.revill@thomsonreuters.com))