(Reuters) - Austrian sensor chip maker AMS AG has warned of a setback with one of its customers which could hit revenues and force a writedown in its accounts, sending its Swiss-listed shares down by as much as 23 percent on Tuesday.<div><a href="http://feeds.reuters.com/~ff/reuters/technologyNews?a=LFPOmSfoLic:UugYNkKvLyE:yIl2AUoC8zA"><img src="http://feeds.feedburner.com/~ff/reuters/technologyNews?d=yIl2AUoC8zA" border="0" /></a> <a href="http://feeds.reuters.com/~ff/reuters/technologyNews?a=LFPOmSfoLic:UugYNkKvLyE:V_sGLiPBpWU"><img src="http://feeds.feedburner.com/~ff/reuters/technologyNews?i=LFPOmSfoLic:UugYNkKvLyE:V_sGLiPBpWU" border="0" /></a> <a href="http://feeds.reuters.com/~ff/reuters/technologyNews?a=LFPOmSfoLic:UugYNkKvLyE:-BTjWOF_DHI"><img src="http://feeds.feedburner.com/~ff/reuters/technologyNews?i=LFPOmSfoLic:UugYNkKvLyE:-BTjWOF_DHI" border="0" /></a></div><img src="http://feeds.feedburner.com/~r/reuters/technologyNews/~4/LFPOmSfoLic" height="1" width="1" alt="" />