It is well established that covenants not to compete do not violate the antitrust laws so long as they are reasonable.

Second, the restraint must be " `reasonably necessary'to achiev [e] that transaction's pro-competitive purpose. "Id

"Non-ancillary" restraints are usually the subject of antitrust action under the Sherman Act, while "ancillary" restraints are usually left to state law.

The "ancillary restraints" that are often important to collaborative ventures, such as agreements between the collaborators not to compete against their joint venture, are also assessed under the rule of reason.

—covenants in restraint of trade include all of those upheld as valid at the common law; but it would certainly seem to follow from the tests laid down for determining the validity of such an agreement that no conventional restraint of trade can be enforced unless the covenant embodying it is merely ancillary to the main purpose of a lawful contract, and necessary to protect …

To be lawful,] the contract must be one in which there is a main purpose, to which the covenant in restraint of trade is merely ancillary.

When two partners set the price of their goods or services they are literally "price fixing," but they are not per se in violation of the Sherman Act.

As announced callously by defendants and above quoted, after they harassed plaintiff into submission they intended moving along to the next processor, with the unmistakable objective, found by the trial judge, of destroying their major competitor, Dairymen's Co-Operative Sales Association and taking over the Western Pennsylvania milk products field.

Courts reviewing complex business arrangements should, in other words, be wary about invitations to "set sail on a sea of doubt."

And in general the liability of stockholders to assessment under local statutes is deemed transitory in nature, enforceable by common-law remedies in states other than that of the corporation, although special statutory forms of remedy given by the local statute could not be resorted to elsewhere.