Dart acquired the remainder of the company in 1997 after exercising a complicated buy-sell agreement with the Herman family.
Mr. Cannon suggested having a buy-sell agreement to deal with such issues.
These included buy-sell agreements in which producers swapped oil with each other at artificially low prices and then resold it at higher prices.
But a complex buy-sell agreement is making that divorce difficult by creating problems even as it solves some old ones.
Wesray Capital had reportedly refused to put up the capital unless a buy-sell agreement was created to part the partners.
It also has a buy-sell agreement with Pacific Telesis for pops in the San Francisco franchise.
Frequently, a buy-sell agreement says that if one major stockholder dies, the other shareholders will buy the business interest from his or her estate.
Mr. Willens named three ways a buy-sell agreement can be structured to avoid springing the tax trap.
Mr. Malane often writes buy-sell agreements so that after the owner's death, the key employee has an option to buy additional shares.
"I design buy-sell agreements so the kids can get the key employee out," Mr. Malane said, although it will cost them money.