The printer maker's shares tumbled 16.3% to 20.36 after it warned of lower-than-expected Q2 profit late Thu. The news also sent Hewlett-Packard (HPQ) and Xerox (XRX) shares falling. Lexmark (LXK) now sees Q2 EPS of 87-89 cents, down from 95 cents-$1.05 earlier. The company cited a weaker-than-expected demand environment, particularly in Europe, and a larger-than-expected impact from unfavorable changes in currency exchange rates as reasons for the revised guidance. Hewlett-Packard shares fell 1.9% to 18.98. Xerox shares fell 1.8% to 7.27.