Correction: May 12 North Sea physical, derivative crude

The Dated Brent assessments for May 12, 2011, were incorrect.

The correct assessments are as follows.

The assessments appear on pages PGA pages 12, 297 and 610.

Brent DTD -3.08 112.99-113.01 -3.08 DTD NS Light -3.08 112.99-113.01 -3.08 NS Basket -3.03 113.82-113.86 -3.03 NS Dtd strip -3.11 112.29-112.31 -3.11 MED Dtd strip -3.15 112.16-112.18 -3.14 BTC Dtd strip -3.16 112.10-112.12 -3.15 WAF Dtd strip -3.19 111.88-111.90 -3.18 Angola Dtd strip -3.17 111.95-111.96 -3.18 CAN Dtd strip -3.19 111.77-111.79 -3.19 Brent CFD assessments (at 4:30 PM local London time)

BRENT Low/High Mid $/bbl Assessment Point Week 1 vs Jul -0.51 0.74 /0.76 -0.51 +0.750 Week 2 vs Jul -0.24 0.55 /0.57 -0.24 +0.560 Week 3 vs Jul -0.21 0.38 /0.40 -0.21 +0.390 Week 4 vs Jul -0.30 0.19 /0.21 -0.30 +0.200 Week 5 vs Jul -0.30 0.04 /0.06 -0.30 +0.050 Week 6 vs Jul -0.28 -0.09 /-0.07 -0.28 -0.080 Week 7 vs Jul -0.26 -0.20 /-0.18 -0.26 -0.190 Week 8 vs Jul -0.27 -0.31 /-0.29 -0.27 -0.300 Sulfur De-escalator: 0.40

Dated Brent Swaps BRENT Low/High Mid $/bbl Assessment Point Week 1 -3.53 112.53/112.57 -3.53 +112.550 Week 2 -3.26 112.34/112.38 -3.26 +112.360 Week 3 -3.23 112.17/112.21 -3.23 +112.190 Week 4 -3.32 111.98/112.02 -3.32 +112.000 Week 5 -3.32 111.83/111.87 -3.32 +111.850 Week 6 -3.30 111.70/111.74 -3.30 +111.720 Week 7 -3.28 111.59/111.63 -3.28 +111.610 Week 8 -3.29 111.48/111.52 -3.29 +111.500