Embattled oil major BP is said to be getting an at-cost rate from competitor Petrobras for the charter of a US-flag shuttle tanker for use in its Gulf of Mexico clean-up efforts.

Tanker brokers believe Petrobras is letting BP have the 46,900-dwt Overseas Cascade (built 2009) for approximately $60,000 per day — which is believed to be Petrobras’s own daily cost of chartering the ship from Overseas Shipholding Group (OSG) — for use at the site of the Deepwater Horizon underwater gusher.

“If