CHICAGO — Magellan Midstream Partners LP and Occidental Petroleum Corp. said they are proceeding with the construction of a 400-mile, 20-inch-diameter crude oil pipeline running from Colorado City, Texas, to Houston’s Gulf Coast area.

Dubbed the BridgeTex Pipeline, the project is also expected to include nearly 50 miles of 24-inch-diameter pipeline between East Houston and Texas City, the companies said in a release Monday. The pipeline is expected to be in service by mid-2014, assuming the necessary permits are obtained, they said.

Magellan, a Tulsa, Okla.-based petroleum products storage and transportation company, and Occidental, a Los Angeles-based oil and gas exploration and production firm, said they made the decision to proceed with the previously announced pipeline after receiving long-term transportation commitments. The decision also follows a recent ruling by the Federal Energy Regulatory Commission approving the pipeline’s tariff structure, the companies said in the release.

The BridgeTex Pipeline is expected to transport crude oil to refineries along the Houston Ship Channel and in Texas City, as well as to other refineries on the Gulf Coast via third-party pipelines, Magellan and Occidental said.