Publicly traded Air Products and Chemicals has bolstered its PR with outside counsel as it falls in the crosshairs of activist investor William Ackman.

air productsAckman has taken a 9.8% ($2.2B) stake in the $10B-a-year Lehigh Valley, Pa.-based supplier of specialty gases like hydrogen.

Air Products in relying on Sard Verbinnen & Co for PR support. George Noon, director of corporate communications, is spokesman for the company.

SV&C chairman/CEO George Sard and managing director Dave Reno are working with AP. The New York-based firm worked with Air Products in its failed $5.1B hostile bid for Airgas in 2010.

Air Products last week adopted a poison pill shareholder rights provision as trading in its shares surged.

After Ackman went public with his investment through Pershing Square Capital Management this week, Air Products defended its performance "in a very challenging environment" and said it welcomes new investment. "Air Products maintains an active dialogue with and carefully considers the views of its shareholders," the company said. "[AP] has not been contacted by Pershing Square Capital Management but welcomes new investors and looks forward to engaging with Pershing Square to understand its views."

The Wall Street Journal reported this month that Ackman told investors he would be raising up to $1B for a new investment fund targeting a single company, which he did not disclose at the time.

Ackman, whose hedge fund is working with Global Strategy Group and Edelman in its high-profile campaign against Herbalife, disclosed his Air Products stake on CNBC's "Squawk Box" on July 31.