HOUSTON: Oil prices closed lower on Friday, marking a 4% weekly decline as a supply glut and a potential Russia-Ukraine peace deal outweighed worries about any impact from the US seizure of an oil tanker near Venezuela.

Brent crude futures settled 16 cents down at US$61.12 a barrel, while US West Texas Intermediate crude was down 16 cents at US$57.44. Both benchmarks fell by about 1.5% on Thursday and have lost more than 4% this week.