Hewlett-Packard Co. said it formed an Internet business unit designed to boost sales of its electronic commerce and computer security software. The unit's products include Internet banking software, electronic commerce devices and Chai, HP's home-grown version of Sun Microsystems Inc.'s popular Java software. The Palo Alto-based computer maker, which said last week that it will split itself in two to improve performance, also plans to unveil a $100-million advertising campaign to tout its Internet-related products. The new unit will consist of five divisions. One of them will include Verifone, which makes machines used in stores for credit card and debit card purchases. Others will focus on Internet security, traditional e-commerce and e-services. HP shares fell $2.19 to close at $67.60 on the New York Stock Exchange.