LONDON MARKETS: FTSE 100 Logs Worst Week Since 2011

By Carla Mozee, MarketWatch

LONDON (MarketWatch) -- U.K. stocks slumped Friday, pushing the FTSE 100 benchmark to its worst weekly drop in more than three years.

The FTSE 100 fell 2.5% to 6,300.63, a fifth consecutive decline, rounding out a week when oil prices tumbled to five-year lows and investors continued to fret about slower global growth. The London benchmark slumped 6.6% for the week, the largest such drop since August 2011, according to FactSet.

The markets are wrestling with the question of whether lower oil prices are a symptom or a cure for weak global demand, said Laith Khalaf, senior analyst at Hargreaves Lansdown, in a note Friday. While the answer is probably a mix of both, the "restorative qualities of a lower oil price are going to take some time to feed through, and, in the meantime, markets are focusing on the negatives."

The oil and gas group fell 3.2% on Friday, led by oil-services provider Petrofac Ltd. , whose shares have taken a beating as of late. They lost 6.4% on Friday, their seventh decline in the past eight sessions. The shares lost 12.9% for the week. They are also driving toward a 45% yearly drop, which would mark their worst year since they began trading in 2005.

Among miners, Randgold Resources PLC gave up 2.6% and Anglo American PLC fell 3.2%. Citi analysts said Anglo American's free cash flow in 2015 "will remain under pressure even if we see some recovery in commodity prices from here."

Only shares of two companies in the FTSE 100 ended higher: utility companies United Utilities PLC and Severn Trent PLC rose 2.9% and 0.5%, respectively.

Subscribe to WSJ: http://online.wsj.com?mod=djnwires