United upgrading service to Hawaii from SFO

United Airlines is adding wide-body planes on San Francisco International Airport, or SFO, routes to the four main Hawaiian islands, meaning that many flights will offer lie-flat seating in Polaris business class for summer travel. The move signals the level of demand United expects to see for travel to Hawaii from the Bay Area this summer and lets it leverage a competitive advantage over Southwest Airlines and some other competitors. "We're seeing strong demand from SFO and LAX to Hawaii, so…