The original bid was all paper and included large amounts of debt.
For one thing, United's original bid came little more than a year after the attacks, and emotions within the carriers were still raw, he said.
Last week, he sweetened his original bid of $19 a share to $22 in cash and preferred stock.
But he noted that the board of directors last month rejected the original bid.
The total cost of the project was over double the original bid, totaling $13.7 million, due to the delays.
Analysts said the offer was increased because Heritage's outside directors were believed to consider the original bid too low.
But one executive who has seen the offer said it exceeded the company's original $600 million bid.
The original bid has been trimmed by $8 million since it was first announced last month.
Is the final cost of a project equal to the original bid?
We must stick to our original bid of minus 15 % by the year 2010.