HOUSTON (Reuters) - Pioneer Natural Resources Co Chief Executive Tim Dove on Tuesday said proposed tariffs on imported steel and aluminium would negatively impact his shale oil production company's returns.

Dove's statement at the CERAWeek energy conference in Houston echoed several other energy executives who this week said there are certain types of metal that are not made by U.S. companies. The Trump administration has proposed putting a 25 percent tariff on steel and 10 percent tariff on aluminium to protect U.S. metal producers and jobs.

(Reporting by Ernest Scheyder; Editing by Tom Brown)