By Christopher Whittall 

Global stocks were little changed Friday as investors remained cautious ahead of comments from Federal Reserve Chairwoman Janet Yellen that could offer clues on the timing of a U.S. interest-rate increase.

The Dow Jones Industrial Average and the S&P 500 both gained around 0.1% in early trade. The Nasdaq Composite Index also edged higher.

U.S. stocks closed marginally lower Thursday following two days of gains.

The Stoxx Europe 600 inched higher after Asian stock markets ended higher.

Ms. Yellen's scheduled remarks at Harvard University will cap a week of comments by Fed officials. Investors will watch to see if she echoes comments from some of her colleagues that interest rates could be raised soon.

"There is very little barrier to another rate hike," said David Stubbs, global market strategist at J.P. Morgan Asset Management, who expects the Fed to move in June or July.

Mr. Stubbs said that inflation is moving in the right direction, financial conditions have improved from the start of the year and there is "good momentum" in the labor market -- all green lights, in his view, for another rate increase.

After previously discounting a June rate rise, investors have begun to consider the possibility more closely in recent days.

Federal-fund futures, used by traders to place bets on central-bank policy, show that the odds for a rate increase at the Fed's June meeting are 24%, up from 4% earlier this month, according to CME Group. Meanwhile, futures markets suggest a 55% chance of a move by the end of the Fed's July meeting.

The euro fell 0.3% against the dollar to $1.115 Friday, while the dollar edged lower versus the yen. The WSJ Dollar Index is up nearly 3% this month as investors have considered the prospect of a June or July rate increase -- a move that would be expected to boost the dollar.

Federal Reserve Board Governor Jerome Powell said Thursday it may be appropriate to raise rates again "fairly soon", while Federal Reserve Bank of St. Louis President James Bullard signaled he is keeping an open mind going into the bank's June meeting.

Investors were also digesting U.S. gross domestic product numbers released Friday that showed the economy's first-quarter slowdown was less pronounced than initially thought. GDP expanded at a 0.8% seasonally adjusted annual rate in the first three months of 2016, revised up from an initial estimate of 0.5%.

In commodities, Brent crude oil slipped 1.5% to $49.41 a barrel after rising above $50 a barrel during early Asian trade.

A recent rally in energy prices helped propel global stocks higher in recent months after steep falls at the start of the year. Brent crude is up over 8% from a month ago and 33% on the year, mainly thanks to disruptions to production and pipelines that have cut supply.

The rise has relieved pressure on risky assets such as stocks and high-yield debt, which fell sharply in line with oil prices at the start of the year on concerns over a low oil price pushing up defaults in the energy sector.

"The main driver of markets this year has been what's going on in commodities," said Mr. Stubbs, who noted that the higher oil price should boost inflation expectations and feed into the Fed's considerations over interest rates.

Mr. Stubbs said oil at around $50 to $60 a barrel is still cheap for consumers without being too painful for producers.

"It is basically a sweet spot," he said.

Asian markets ended mostly higher Friday. Japan's Nikkei Stock Average was up 0.4% after data released Friday showed Japanese consumer prices fell again in April. The continuing falls could add to pressure on the Bank of Japan to unveil more easing measures to boost inflation -- a move that can support stocks.

Australia's S&P/ASX 200 rose 0.3%, notching up its seventh-straight week of gains.

Elsewhere in commodities, gold fell 0.1% to $1219.20 an ounce.

Write to Christopher Whittall at christopher.whittall@wsj.com

(END) Dow Jones Newswires

May 27, 2016 09:52 ET (13:52 GMT)