A slump in technology shares on Wednesday helped turn early gains in U.S. stock indexes into losses across industries, extending the market’s losing streak to a third day.

Investors sent the Dow Jones industrial average up 200 points in morning, then began dumping some big tech stocks. Apple fell 2.2 percent and Microsoft lost 1.5 percent.

By the end of the day, seven of the 10 industry sectors in the Standard and Poor’s 500 index fell. Suppliers of raw materials, the focus of aggressive selling in recent days, rose 3.1 percent as investors hunted for bargains.

“You’ve got two days of massive selling of oil and commodity companies, so perhaps some are oversold,” said Bryn Mawr Trust chief investment officer Ernie Cecilia.

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The Dow index lost 75.70 points, falling to 17,492.30. The Standard & Poor’s 500 index gave up 0.77 percent to close at 2,047.62. The Nasdaq composite dropped 1.48 percent to 5,022.87.

Helping boost raw material stocks were news reports that two giant chemical companies, Dow Chemical and DuPont, were in talks to combine. Dow Chemical rose 11.93 percent to $56.97. E.I. Du Pont De Nemours And Co. climbed 11.83 percent to $74.49.— AP