July 15 (Reuters) - Major Gulf stock markets rose at the start of trading on Wednesday after the United States abandoned plans to impose tariffs on shipping through the Strait of Hormuz, while an unexpected slowdown in the U.S. inflation rate dampened expectations of an interest rate hike.

US President Donald Trump reinstated a naval blockade on Iranian ports on Tuesday and threatened to bomb power plants and bridges next week unless Iran returns to negotiations aimed at ending the conflict.

He backed away from an earlier proposal to impose a 20 percent fee on shipping through the Strait of Hormuz and said that instead he would seek to strike investment deals with Gulf states, without providing details.

Dubai's main index rose 1 percent, with Emaar Properties shares climbing 1.4 percent and Emirates NBD shares gaining 1 percent.

In Abu Dhabi, the index rose 0.4 percent.

The UAE Ministry of Defense announced on Tuesday that an Indian sailor was killed and eight others were injured after two Emirati oil tankers were targeted by Iranian cruise missiles in the Strait of Hormuz.

The Saudi index rose 0.1 percent.

Federal Reserve officials welcomed the slowdown in inflation in June, but said more evidence was needed to confirm that price pressures were easing.

The U.S. Producer Price Index data, due to be released later today, may provide further clues about inflation and monetary policy expectations.

According to the CME FedWatch tool, traders now expect a US interest rate hike in September at 58 percent, compared to 76 percent before the Consumer Price Index report, while the probability of a rate hike in December remains close to 80 percent.

US monetary policy affects the markets of the Gulf countries, where most currencies are pegged to the dollar.

The Qatar Stock Exchange remained closed following the death of former Emir Sheikh Hamad bin Khalifa Al Thani.