Siebel Systems Inc. founder Tom Siebel stepped down as CEO last week to make room for 25-year IBM Corp. veteran Mike Lawrie, who most recently headed Big Blue's sales and distribution operations. Siebel remains the company's chairman. Industry watchers called the executive change a shock, but a welcome one. The CRM software maker still holds the lead in market share, but the vendor's growth slowed in recent years as it confronted a downturn in software buying and increased competition from SAP AG, PeopleSoft Inc. and Oracle Corp. Someone new with a fresh approach to sales is a good thing for Siebel, analysts say.