A contract network extends the concept of a contract path to address the problem of loop flow and congestion in electric power transmission systems. A contract network option provides an internally consistent framework for assigning long-term capacity rights to a complicated electric transmission network. The contract network respects the special conditions induced by Kirchoff's Laws; accommodates thermal, voltage, and contingency constraints on transmission capacity; and can be adopted without disturbing existing methods for achieving an economic power dispatch subject to these constraints. By design, a contract network would maintain short-run efficiency through optimal spot-price determination of transmission prices. Through payment of congestion rentals, the contract network makes a long-term capacity-right holder indifferent between delivery of the power or receipt of payments in a settlement system.