Marathon Petroleum is delaying the final investment decision (FID) on its planned residual oil upgrader expansion at its 522,000-bpd Garyville refinery in Louisiana.

"We believe this project has great potential returns, but we are deferring a final investment decision as we further evaluate the implications of current market conditions on the project," CEO Gary R. Heminger said in a statement issued with regards to the company's 2015 capital investment plan.

The company's investment plan of $2.53 billion includes $1.28 billion for its refining and marketing segment and $659 million for its pipeline transportation business.

Within the refining business, roughly $235 million is earmarked for midstream investments and $370 million for refining margin enhancement projects.

"Our focus for refining in 2015 is to invest in projects that enhance our overall return," Heminger said.

"For example, we are continuing to invest in projects to improve connectivity between our Galveston Bay and Texas City refineries, which will allow us to realize additional synergies through the integration of these two refineries."