US-based S1 Corporation has appointed its co-founder and chairman James Mahan CEO, replacing Jaime Ellertson.
Mahan originally served as CEO from 1995 through to 2000 before being replaced by Ellertson. The vendor did not disclose the reason behind Ellertson's departure.
Atlanta-based S1 also released preliminary results for Q2 2005 and is forecasting second-quarter revenue of $62 million to $62.5 million and earnings of two to three cents per share, in line with guidance.
But revenue from financial institutions is expected to be $54 million to $54.5 million, slightly below the vendor's previous outlook.
Subscription revenue is expected to be about $1.7 million, ahead of guidance of $1.3 million.
S1 shares were down 37 cents, or 6.84%, to $5.04 in mid-morning trading on Nasdaq.