Merger negotiations between United Airlines and Continental Airlines (CAL) are hobbling along as the two sides continue to bicker over how to calculate the share price used in a potential stock-swap deal, Dow Jones reported.

"It's the elephant in the room, the only issue left to resolve," said one person close to the situation. If it doesn't get resolved in the next few days, this person added, it's likely to scuttle a combination that would be the world's largest airline by traffic. In previous merger talks in 2008, Continental spurned United as a partner.