Fines under the Clean Water Act could top $17 billion, an amount more than BP's profit in 2013, which after items was $13.4 billion.

U.S. District Judge Carl Barbier in New Orleans has considerable leeway and could assess a much smaller fine after the third and likely final stage of the trial, which will assess the environmental impact of the largest offshore spill in U.S. history. The third phase will run from January 20 to February 5 of 2015.

The trial's first phase dealt with the issue of negligence and concluded last April. The second phase of the trial, which ended last October, focused on estimating how many million barrels of oil leaked from the blown out Macondo well for 87 days after the accident that killed 11 workers. Findings from the first two phases will affect the size of the fines.

BP has set aside more than $42 billion in provisions for cleanup, compensation and fines since the spill.

Separately on Tuesday, the British major said it had agreed to sell interests in four, mature BP-operated oilfields and related pipelines on the North Slope of Alaska to the production company Hilcorp as it works to invest in new opportunities there.

(Reporting By Terry Wade)