One of the most difficult problems in multidatabase transaction processing is to guarantee the multidatabase consistency in the presence of failures while preserving local autonomy. To solve this problem, a resilient global atomic commitment protocol having appropriate recovery mechanisms should be provided. In this thesis, we investigate a reliable atomic commitment protocol for multidatabase transaction processing. We design and implement a global transaction manager that guarantees a global atomic commitment even in the presence of failures. Our global transaction manager effectively utilize the existing resources while preserving maximum local autonomy and does not place the restriction on the multidatabase transactions processing that are often assumed in the previous works.