TVK Selects aspenONE Advanced Process Control for Major New Ethylene and Polyethylene Plants.

Leading petrochemical producer implements solutions to improve financial performance of new facilities

CAMBRIDGE, Mass. -- Aspen Technology, Inc. (NASDAQ: AZPN), today announced that Tisza Chemical Group (TVK), a leading petrochemical producer in Central Europe and member of the MOL Group, is implementing aspenONE Advanced Process Control applications at two major new ethylene and polyethylene plants. These applications will enable TVK to improve the financial returns from the two plants by maximizing production, increasing yields, reducing waste material and improving product quality.

"TVK's petrochemical development program has helped the company become one of the largest polymer producers in Central Europe, and AspenTech's Advanced Process Control applications will enable us to improve the financial performance of our new facilities," said Mr. Arpad Deak, Petrochemical Technology & Project Development Director, TVK. "We selected the integrated aspenONE applications over competitive offerings because of their best-in-class technology, and the industry knowledge and experience provided by AspenTech's ethylene and polymers specialists."

The aspenONE Advanced Process Control for Chemicals application applied to the new Linde-design ethylene plant combines advanced process control (APC) and real-time optimization (RTO). This optimizes throughput by pushing the process to multiple constraints simultaneously and holding it there safely. The optimum operating point is established by the RTO solution which utilizes an on-line rigorous process model that is constantly updated by real-time operating data. The on-line model can also be used off-line to allow process engineers to perform operational excellence studies, such as de-bottlenecking and what-if studies.

The new Mitsui high density polyethylene (HDPE) plant is being optimized using the aspenONE Advanced Process Control for Polymers application. This production control solution is based on the Aspen Apollo[TM] non-linear control technology which is specifically designed for the complex behavior of polymer processes. The application optimizes process performance in both steady-state and transitions, delivering increased yield and throughput, faster transition times, minimized off-specification product and reduced process variability.

"TVK's decision to select our aspenONE for Advanced Process Control applications for their major new facilities highlights our continued leadership in the APC market and reflects the growing demand for our products in Central and Eastern Europe," said Blair Wheeler, Senior Vice President, AspenTech. "The extensive chemicals and polymers industry experience of our consultants and implementation teams will help to ensure that TVK realizes sustained value from the solutions and further enhances its competitive position."

License revenue from this project was recognized in the fiscal quarter ended June 30, 2006.

About TVK

Tisza Chemical Group Plc. (TVK Plc.) operates the largest petrochemical complex in Hungary. An integrated production company, TVK makes ethylene and propylene from naphtha and gas oil that are processed using world-class technology to produce low-, medium- and high-density polyethylene and polypropylene. The company is the market leader in Hungary, and more than 50% of its products are marketed abroad. TVK is part of the MOL Group Petrochemical Division, one of the largest integrated polyolefin producers in Central Europe. For more information, visit www.tvk.hu.

About AspenTech

Aspen Technology, Inc. provides industry-leading software and professional services that help process companies improve efficiency and profitability by enabling them to model, manage and control their operations. The new generation of integrated aspenONE[TM] solutions is aligned with the key industry business processes, providing manufacturers the capabilities they need to optimize operational performance, make real-time decisions and synchronize the plant and supply chain. Over 1,500 leading companies already rely on AspenTech's software, including Bayer, BASF, BP, Chevron Corporation, DuPont, ExxonMobil, Fluor, GlaxoSmithKline, Sanofi-Aventis, Shell and Total. For more information, visit www.aspentech.com.

This press release may contain forward-looking statements for purposes of the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. Actual results may vary significantly from AspenTech's expectations based on a number of risks and uncertainties, including, without limitation: AspenTech's plan to improve operational performance may not be implemented effectively; AspenTech has identified material weaknesses in its internal controls with respect to software license revenue recognition and other matters, that, if not remedied effectively, could result in material misstatements; risks around securities litigation and investigations; AspenTech's lengthy sales cycle makes it difficult to predict quarterly operating results; fluctuations in AspenTech's quarterly operating results; AspenTech's dependence on customers in the cyclical chemicals, petrochemicals and petroleum industries; the possibility of new accounting standards or the interpretation of existing accounting standards affecting our financial results; AspenTech's ability to raise additional capital as required; intense competition; AspenTech's need to develop and market products successfully; reliance on relationships with strategic partners; challenges associated with international operations; and other risk factors described from time to time in AspenTech's periodic reports filed with the Securities and Exchange Commission. AspenTech cannot guarantee any future results, levels of activity, performance, or achievements. AspenTech expressly disclaims any current intention to update forward-looking statements after the date of this press release.

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