Irving Oil Ltd, the privately held firm that operates Canada's largest refinery, said on Thursday that Paul Browning, the chief executive it appointed only last year, has left the company, though it offered no detail on the reason for his departure.

Samantha Robinson, a spokeswoman for the company, confirmed in an email that Browning, a former General Electric Co executive, had departed the family-owned company but did not say when he had left or when a successor would be named.

"We can confirm that Paul Browning is no longer with Irving Oil. We thank Paul for his contributions and we wish him every success in his future endeavors" Robinson wrote.

Irving operates a namesake 300,000 barrel-per-day refinery in Saint John, New Brunswick, and exports much of its production to the U.S. Northeast and operates more than 800 Irving-branded service stations, primarily in Eastern Canada and New England.

Browning had previously been chief executive of thermal products for GE's Power and Water Division.