In 2000, Andritz bought the first 50% stake in Ahlstrom Machinery Group, making Andritz a leading global supplier of production systems for all types of pulp, including chemical recovery systems.  The second 50% stake was acquired in June 2001.

In November 2000 Andritz acquired Universal Milling Technology (UMT), the feed technolgy business of the British Tate & Lyle PLC. With this acquisition Andritz also became a global market leader in the area of feed technology.

In June 2001 Andritz went public on the Vienna Stock Exchange. 2 million newly issued shares were placed successfully with national and international investors.

In the following years Andritz continued its strategy of acquiring companies active in complementary business fields:

In October 2002 Andritz acquired the furnace technology division of SELAS SAS, a French subsidiary of SELAS Corp., USA.  With this acquisition Andritz has become a supplier of complete plants for continuous hot-dip galvanizing.  Combining the capabilities of the affiliates Sundwig, Andritz-Ruthner and SELAS, Andritz covers almost the complete process line for hot-dip galvanizing.

The purchase of ABB Drying in December 2002 extended the Andritz product program for pulp drying and baling line equipment.  Andritz is now supplier of the entire range of products from the woodyard to production of all kinds of pulp to equipment for making pulp bales that are ready for dispatch.

In 2003 Andritz further strengthened its service offering to the pulp and paper industry by acquiring IDEAS Simulation Inc., a leader in dynamic process simulation, and Acutest Oy, a supplier of acoustic condition monitoring systems.  

In June 2003, the public offer of shares of Andritz AG to retail investors in Austria and the private placement to institutional investors (in reliance on Regulation S) have been executed successfully.  The offering consisting of 5,664,538 shares plus a 7.5% over-allotment option of 424,841 shares from the financial investors (Unternehmens Invest AG, The Carlyle Group, Deutsche Beteiligungs-AG, GE Capital) was subscribed several times.

With the acquisition of Fiedler in September 2003 Andritz further strengthened its services business and has become one of the world’s leading suppliers of screen baskets.

Bird Machine, which was acquired in January 2004, adds large centrifuges and filter presses for municipal and industrial applications as well as relevant services to the product portfolio of the Environment and Process Business Area.  

The NETZSCH Filtration Business Unit acquired in June 2004 supplies different types of dewatering units, in particular filter presses, for solid/liquid separation in industrial and municipal applications.

In September 2004, Andritz purchased certain assets and know how of insolvent Otto Kaiser GmbH, headquartered in Bretten, Germany, a manufacturer of high-performance mechanical presses for the processing of steel strip into stampings and drawing parts. 

In November 2004, Andritz acquired the globally active Fluid Bed Drying Systems Business Area of VA TECH WABAG, Ravensburg, Germany, which is specialized in the development, production and erection of plants for granulation and drying of solutions, suspensions, and bulk materials.

In July 2005, Andritz acquired 100% of Lenser Filtration, Germany, one of the leading global manufacturers of filter elements from thermoplastic materials for solid / liquid separation in filter presses.

In April 2006, Siemens Austria and Andritz AG signed a purchase agreement for the acquisition of the hydropower section of VA TECH HYDRO.  Following the approval by the relevant antitrust authorities, the parties closed the transaction successfully at the end of May 2006.

In May 2006 Andritz acquired a 60% stake in the Paper and Nonwoven Business Areas of Eduard Küsters Maschinenfabrik GmbH & Co. KG, based in Krefeld, Germany. Kuesters is one of the world´s leading suppliers of rolls and calender technology to the paper, non-woven and textile industries.  And n June 2006, Andritz purchased the remaining 40% stake in the Paper and Nonwoven Business Areas of Eduard Küsters Maschinenfabrik GmbH & Co. KG from Jagenberg AG.  Andritz Küsters is now 100% owned by Andritz.

In June 2006, Andritz successfully placed a 200 million Euro corporate bond with a coupon of 4.5% and a tenor of 7 years.  Demand for the bond was very strong, with investors outside Austria also participating substantially in the transaction.  Approximately 25% of the volume was placed with retail investors.

In December 2006, Andritz acquired the Coater Division for paper production from Bachofen + Meier AG (BMB) based in Bülach, Switzerland. As a globally leading specialist for technologies and systems for paper coating, BMB complemented the Andritz product portfolio in the area of paper and board production equipment.

In June 2007, Andritz purchased 50% of Brazilian Sindus Human Technology, the leading provider of automation, instrumentation and electricity maintenance services for the pulp and paper industry in Brazil.

In December 2007, Andritz acquired Tiszakécskei Gépgyár Kft. (Tigép), Tiszakécskei, Hungary.  Tigép – now Andritz Kft. – produces high-level components for turbo-generators and gas turbines for renowned international groups, as well as other welded machine parts for certain specialized industries.

In March 2008, Andritz acquired 100% of MAERZ-Gautschi Industrieofenanlagen GmbH, Düsseldorf, Germany from Hochtemperatur GmbH, a company of Deutsche Beteiligungs AG. MAERZ-Gautschi is one of the world's leading companies for heat treatment plants and melting furnaces.

In May 2008 Andritz purchased hydropower technology and certain other assets of GE Energy's Hydro business, including engineering and project management resources, research and development capabilities, and specialized generator component production facilities in Canada. In June 2008, Andritz acquired GE Energy's majority interest in the GEHI (General Electric Hydro Inepar) joint venture, which has sales, engineering, and project management resources in Brazil, Finland, and Sweden, as well as test facilities and manufacturing sites.