The warrant is expected to be priced at about a 12.5 percent premium over Berkshire's current stock price.
The price represents about a 24 percent premium to today's closing price for Seagate of $62.75.
But if announced, the purchase price would be about a 10 percent premium over Airtouch's closing price yesterday of $72.4375.
That would represent about a 70 percent premium to Intermedia's closing price on Friday of $22.88.
Already Phelps Dodge was offering about a 40 percent premium to buy the companies, "we thought we'd gone far enough," he said.
That is about an 18 percent premium over Gillette's shares.
That would be about a 31 percent premium over Immunex's closing price on Wednesday, before the talks were reported.
Based on yesterday's closing price of $56.250 a share, this represents about a 15 percent premium over the price after the split.
That represents about a 4.3 percent premium over the share price of $26.75 yesterday.
The companies are discussing a nearly all-stock transaction that would represent about a 20 percent premium over Lucent's current value of $33.5 billion.