GLOBAL MARKETS - Stocks rise, dlr slides ahead of Fed

By Natsuko Waki

LONDON (Reuters) - World stocks rose from the previous day's four-week low on Wednesday while the dollar slipped ahead of a policy decision by the Federal Reserve, expected to affirm its commitment to ultra-low interest rates.

Wall Street looked set for a positive start.

A survey showed the euro zone's dominant service sector expanded for the second consecutive month and at its fastest pace in 22 months, adding to encouraging economic signs, though Germany's expanded at its slowest rate in three months.

The Fed is expected to pledge to hold benchmark interest rates exceptionally low for "an extended period" while acknowledging some positive economic development.

"The Fed is unlikely to offer any hints into the timing of an exit strategy and eventual rate rises, which may help stocks to rise and consequently boost (the euro)," said Antje Praefcke, currency strategist at Commerzbank in Frankfurt.

The MSCI world equity index rose 0.7 percent while the FTSEurofirst 300 index gained 1 percent.

"The macro data flow has been very positive over the last couple of days and I think the markets can go a bit higher from here," said Klaus Wiener, research head at Generali Investments.

Markit's final euro zone services purchasing managers' index of around 2,000 companies rose in October to 52.6, its highest reading since December 2007, up from 50.9 in September.