U.S. stock index futures advanced on Friday after four consecutive days of losses as investors awaited Friday's key U.S. payroll report.

U.S. nonfarm payrolls, due at 8:30 a.m., are seen rising by 186,000 last month, according to a Reuters survey of economists. In March payrolls rose by 216,000 which was the biggest increase in 10 months.

The benchmark S&P 500 has fallen 2.1 percent this week on a string of soft economic data, culminating in a drop in commodity prices on Thursday as demand deterioration concerns increased.

U.S. crude futures shed 1.5 percent to $98.33 and ICE Brent futures lost 0.9 percent to $109.80.

S&P 500 futures gained 3.7 points and were above fair value, a formula that evaluates pricing by taking into account interest rates, dividends and time to expiration on the contract. Dow Jones industrial average futures added 25 points, and Nasdaq 100 futures rose 8.75 points.

Companies that have posted results on Friday include Constellation Energy Group , Northeast Utilities , Pepco Holdings
, with The Washington Post Company still expected to report.

Through Thursday, with 421 of the S&P 500 companies having reported quarterly earnings, 68 percent had profits that beat Wall Street expectations, according to Thomson Reuters data.

European shares dipped as caution prevailed ahead of a U.S. payrolls report which could point to a slowing of momentum in the world's largest economy. <.EU>

Asian equities clawed back up from the day's lows as market players squared positions before U.S. payrolls data.

Wall Street stock indexes fell for a fourth straight day on Thursday as a massive sell-off in commodities spilled over into other markets, forcing investors out of higher-risk assets and rattling equities markets before Friday's U.S. payrolls data.

( Reporting by Chuck Mikolajczak, Editing by W Simon )