HOUSTON, June 2 (Reuters) - Canadian oil producer

Cenovus Energy ( CVE ) declared force majeure on its supply of

Christina Lake Dil-bit heavy crude due to wildfires in the

oil-producing province of Alberta, two trading sources said.

Companies declare force majeure when unexpected

circumstances prevent them from meeting contractual obligations.

Cenovus said on Sunday it evacuated non-essential personnel

from its Christina Lake oil sands site, and has shut in about

238,000 barrels per day of production since Thursday. The

company said it expects a full restart of operations in the near

term.

It was unclear when Cenovus declared force majeure and the

company declined to comment further.

The wildfires have affected more than 344,000 bpd of oil

sands production, or about 7% of the country's overall crude oil

output, according to Reuters calculations.