UPDATE 2-DuPont cuts sales forecast as China trade war hits home

(Adds 2019 outlook, details on Chinese auto industry, smartphone markets.)

Aug 1 (Reuters) - Industrial materials maker DuPont cut its full-year forecast for core sales on Thursday as it reported worse-than-expected revenue for the second quarter, pointing to weak demand in some of the sectors most affected by the U.S.-China trade war.

The company, one part of conglomerate DowDupont until a split earlier this year, said it now expects full-year organic sales to be slightly down, compared with its earlier forecast of a 2% to 3% rise.

DuPont added it would take more action to cut costs in the second half of the year to offset the fall off in demand from some of its biggest customers in the electronic and automotive sectors.

That allowed it to raise its pro forma adjusted profit forecast to a range of $3.75 to $3.85 per share.

The ongoing trade war between two of the world's largest economies and weakening car and smartphone sales globally have hurt companies like DuPont, which supplies components to a range of industries and supply chains.

China, now the world's single-largest market for both cars and mobile phones, has seen sales in both areas fall in recent quarters, according to industry indicators.

"This change in (sales) expectation is a reflection of the prolonged weakness in our short cycle businesses, primarily automotive and semiconductors," Chief Executive Mark Doyle said on an earnings call.

"Volumes declined 12% due to lower autobuilds, primarily for the China market, weak electronics demand and continued de-stocking in both the automotive and electronics channels," the company said about the transportation and industrial business.

The auto industry is DuPont's largest end market, accounting for about 15% of its total sales, while smart phones represent about 5%.

"Europe and Asia volumes were down mid-teens as China tariff concerns coupled with inventory destocking impacted demand."

Adjusted for charges, the company reported profit of $725 million, or 97 cents per share, in the second quarter ended June 30 from $695 million, or 89 cents per share, a year before.

Revenue fell 6.6% to $5.47 billion, below analysts' estimates of $5.63 billion, according to Refinitiv IBES data. (Reporting by Nishara Karuvalli Pathikkal and Arathy S Nair in Bangalore; Editing by Anil D'Silva)