Express Scripts

(ESRX)

named George Paz CEO, effective April 1, 2005. He will replace Barrett Toan, who will remain chairman.

The pharmacy benefits manager said Tuesday that Paz had been president since last year and was previously chief financial officer since he joined in 1998.

Toan asked the company's board to start a search for a successor in 2003.

"This begins an exciting new chapter for Express Scripts," Toan said. "George is a highly regarded and experienced leader who has demonstrated a commitment to growth, our business model and the enhancement of our value proposition. He knows how to align the Company's priorities with those of our clients, which makes him the right person to lead Express Scripts."

Express Scripts shares fell $1.32 Thursday to $76.08.