CDI Corp., a Philadelphia engineering and technology staffing firm, publicized a $67.6 million cash offer for RCM Technologies Inc. after failing to reach an agreement with RCM's chairman and chief executive, Leon Kopyt, CDI said.

The $5.20-a-share offer represents a 49 percent premium to RCM's close Thursday at $3.50 on Nasdaq. In later trading, the Pennsauken company's shares jumped 40 percent, to $4.90.

RCM, which provides information technology, engineering, and commercial services, reported $189 million in revenue and $7 million in profit in its most recent fiscal year.

RCM said in a statement Thursday evening that CDI's current offer "would not be in the best interests of the company."

CDI, which published a letter sent to RCM board members May 21, said it would take its offer directly to RCM shareholders, if necessary.    - Harold Brubaker