When introducing two people in business, usually the first name that you say is the person who is higher in rank.
Example: “Joe, this is our new Vice President of Sales, Sally Sellsmore. Sally, this is our CEO, Joe Executive.”
However, when introducing anyone in your organization to someone outside your organization, the first name you say is the person outside your organization.
Example: “Hal, this is Sally Sellsmore, our Vice President of Sales. Sally, this is Hal Onwheels, who is a Sales Rep from Must Buy Supply.”
When introducing two people, it is fine to say, “This is . . . ”
“May I present . . . ” or “May I introduce . . . ” is reserved for more formal occasions.
From the Culture and Manners Institute at http://www.cultureandmanners.com