This paper presents the theory of sequential auctions when participants desire more than one unit. The theoretical predictions are compared to experimental data. We estimate structural models which presume that participants' bids are drawn from some stochastic processes. The observed behavior depends highly on the theoretical bid, however some variance in participant bids remains unexplained. The analysis of the model and of the experimental data is completed by some simulations. While the theoretical model predicts increasing prices, on average both the data and the winning bids generated by our structural models exhibit declining prices.