The joint optimization problem of energy procurement and retail pricing for an electricity retailer is converted into separately determining the optimal procurement strategy and optimal pricing strategy, under the "price-taker" assumption. The aggregate energy consumption of end use customers (EUCs) is predicted to solve for the optimal procurement strategy vis a long short-term memory (LSTM)-based supervised learning method. The optimal retail pricing problem is formulated as a Markov decision process (MDP), which can be solved by using deep reinforcement learning (DRL) algorithms. However, the performance of existing DRL approaches may deteriorate due to their insufficient ability to extract discriminative features from the time-series vectors in the environmental states. We propose a novel deep deterministic policy gradient (DDPG) network structure with a shared LSTM-based representation network that fully exploits the Actor’s and Critic’s losses. The designed shared representation network and the joint loss function can enhance the environment perception capability of the proposed approach and further improve the optimization performance, resulting in a more profitable pricing strategy. Numerical simulations demonstrate the effectiveness of the proposed approach.