WASHINGTON (Reuters) - President Barack Obama has tapped the current chief operating officer at the Energy Department's office of fossil energy to lead the unit as assistant secretary.

The White House on Friday announced the plan to nominate Charles McConnell, who joined the department earlier this year after a two-year stint as vice president of carbon management at Battelle Energy Technology. The nomination requires Senate confirmation.

McConnell previously spent 31 years at Praxair Inc, the largest industrial gases supplier in North America. He has also chaired, advised or sat on boards of several industry groups.

The nomination comes as the Obama administration -- known for its focus on green energy -- takes a more active role in oil issues, tapping emergency reserves in a bid to rein in high oil prices.

The office of fossil energy is tasked with helping the country retain access to clean and cheap energy from traditional fuels: oil, gas and coal. It keeps close watch of federal emergency oil stockpiles and works to develop clean coal technology and increase productivity of oil and gas fields.

With the positions of assistant secretary and principal deputy assistant secretary vacant, McConnell has been the highest-ranking official in the fossil energy office as COO.

(Reporting by Alina Selyukh; Editing by Paul Simao)