The boards of the two companies could sign a deal as early as today.
A merger of the two US carriers would create the world’s largest airline, surpassing Delta Air Lines in traffic and revenue.
The two US airlines resumed merger negotiations earlier this month, two years after walking away from similar talks.
Earlier this week, sources said the two companies disagreed over the exact ratio of shares that United planned to pay for Continental in the potential stock-for-stock merger.
Continental wanted to use the so-called “unaffected share prices,” which is the price of the stock before the recent spate of news of airline merger talks. However, United wanted to use a later market price, the source added.
It is understood that United Airlines would be the surviving brand and the combined company would be based in Chicago.