Others close to the talks said the figure was above 15 percent.
The source close to the talks said they had made some progress.
But people close to the talks said that there was little chance of a deal.
Two people close to the talks said any deal would be complicated.
The deal could still fall through, according to people close to the talks.
A person close to the talks said they began about six months ago, and became intense only last week.
One person close to the talks said there was an 85 percent chance that the two companies would complete a deal.
One person close to the talks said at the time that a $500 million price was likely.
"The deal really did come together this morning," said one person close to the talks.
"Things went very well over the weekend," one person close to the talks said.