Reliable and efficient operation of deregulated electricity markets requires supply and demand elasticity. This paper presents incentive control of spinning reserves in electricity multi-markets using game theory. Interruptible load contracts (ILC) could reduce the amount of spinning reserve requirements during system contingencies such as transmission congestion. It is shown that the power utilities (PU) with ILC could increase their benefits in time-separated energy and spinning reserves markets (e.g., inter-temporal market gaming among day-ahead, hour-ahead and real-time markets).