Chevron Corporation announced last week that two of its top executives will assume new roles effective January 1, 2016.

Michael Wirth will become executive vice president for Midstream and Development. Wirth is currently executive vice president, Downstream and Chemicals. Pierre Breber, presently executive vice president, Gas and Midstream, will become executive vice president, Downstream and Chemicals. Both will continue to report to John S. Watson, Chevron’s chairman and chief executive officer.

“Mike and Pierre are experienced leaders, and these moves will allow both to apply their broad experience and management skills to new areas that will generate greater enterprise value,” said Watson.

In his new role, Wirth, 55, will have responsibility for corporate strategy, business development, supply and trading, gas commercialization, and the company’s midstream operating units engaged in transportation and power.

“Mike has systematically improved our downstream performance through portfolio optimization and efficiency,” said Watson. “He will now focus on Chevron’s companywide asset portfolio and strategy while leading the company’s midstream activities.”

As the head of Downstream and Chemicals, Breber, 51, will lead Chevron’s worldwide manufacturing, marketing, chemicals, lubricants and Oronite additives businesses. He also will have oversight of the company’s chemical joint venture, Chevron Phillips Chemical Company.

“Pierre has broad experience in our upstream, midstream and finance organizations. In his new role he will drive additional performance improvements to build on the success of our downstream and chemicals business.”