Complex sentence: The Leading Hotels of the World started as a reservation service for independent hotels and is now a full-service hotel consortium which supports sales and marketing, advertising and public relations, financial services, quality control, and hotel inspections for its member properties.
Split into simpler sentences: The Leading Hotels of the World started as a reservation service for independent hotels. It is now a full-service hotel consortium which supports sales and marketing, advertising and public relations, financial services, quality control, and hotel inspections for its member properties.