Air Products & Chemicals Inc. raised its offer for Airgas Inc. to $70 a share, adding $377 million in cash to its previous bid and saying it will not offer more for the Radnor distributor of industrial and medical gases.

Air Products, an Allentown producer of industrial gases that wants to buy Airgas to expand its customer base, made its first public offer for Airgas at $60 a share in February. The latest offer values Airgas at $5.86 billion, not including debt.

"It is time to bring this matter to a conclusion, and we are today making our best and final offer for Airgas," John E. McGlade, chairman and chief executive of Air Products, said in a news release. McGlade said his company's board had determined that it would not persist in its hostile bid indefinitely.

"If Airgas shareholders want this compelling offer, they must make their voices heard now," he said.

Airgas said in a statement that its board would review the revised offer. Trading in the company's shares was halted pending the announcement, but has since resumed; shares were trading at $62.38, off $3.59.

The Airgas board has said previously that it thinks the company is worth $78 a share.