GLOBAL MARKETS-Dollar rises, stocks firm ahead of Yellen

* U.S (Other OTC: UBGXF - news) . dollar on track for best month since November

* Imminent U.S. rate rises still on investors' minds

* Global stocks edge higher (Updates with U.S. market openings, changes dateline, previous LONDON)

By Saqib Iqbal Ahmed and Caroline Valetkevitch

NEW YORK, May 27 (Reuters) - The U.S. dollar and world stock indexes edged higher on Friday ahead of a speech by Federal Reserve Chair Janet Yellen that could provide new signals on the timing of a U.S. interest rate hike.

Crude oil prices eased after hitting seven-month highs above $50 a barrel the day before.

The dollar added to gains after U.S. data showed economic growth slowed in the first quarter although not as sharply as initially thought. A surge in home building and steady inventory accumulation partially offset modest consumer spending and soft business investment.

Yellen is due to speak at an event hosted by Harvard University at 1:15 p.m. ET (1715 GMT). Numerous Fed officials in recent weeks have talked up expectations that an increase in borrowing costs may be near.

"We're expecting a lot of major data in the next few weeks and Yellen will balance her comments, keeping that in view," said Nadia Lovell, U.S. equity specialist at J.P. Morgan Private Bank in New York.

The Dow Jones industrial average was up 34.93 points, or 0.2 percent, to 17,863.22, the S&P 500 had gained 5.14 points, or 0.25 percent, to 2,095.24 and the Nasdaq Composite had added 19.63 points, or 0.4 percent, to 4,921.39.

MSCI (NYSE: MSCI - news) 's all-country world stock index rose 0.2 percent, while the pan-European FTSEurofirst 300 index of leading regional stocks was up 0.2 percent.

European shares were propped up by the Swiss stock market and pharmaceuticals companies after drugmaker Roche climbed on positive results for one of its products.

Trading volumes were relatively light ahead of public holidays that will close London and New York markets on Monday.

The dollar index was up 0.40 percent and on track for its strongest monthly performance since November.

U.S. Treasury prices slipped ahead of Yellen's speech.

"People are waiting to see whether they would get anything meaningful, but it's highly unlikely she wants to rock the boat before a long holiday weekend," said Larry Milstein, head of government and agency trading at R.W. Pressprich & Co. in New (KOSDAQ: 160550.KQ - news) York.

Benchmark 10-year Treasury notes were down 3/32 in price for a yield of 1.834 percent, up 1 basis point from Thursday. The U.S. bond market will close early at 2 p.m. (1800 GMT) ahead of the long holiday weekend.

In the energy market, Brent fell 52 cents to $49.07 a barrel, retreating from the previous session's $50.51 peak, its highest since early November. U.S. crude dropped 33 cents to $49.15 after touching $50.21 on Thursday, its highest since early October.

Gold (Other OTC: GDCWF - news) slid to an eight-week low and was headed for a fourth consecutive weekly drop on rate hike concerns. Spot gold was down 0.3 percent at $1,215.39 an ounce. (Additional reporting by Richard Leong in New York and Tanya Agrawal in Bengaluru; Editing by Catherine Evans and Nick Zieminski)