DUBAI - DP World , one of the world's biggest port operators, posted a 2.1 percent drop in first-half net profit on Thursday, and cautioned about geopolitical risks and recent changes to trade policies.

U.S. President Donald Trump is taking a more aggressive, protectionist posture on trade than his recent predecessors, sparking retaliatory measures from other countries such as China.

"The near-term trade outlook remains uncertain with recent changes in trade policies and geopolitical headwinds in some regions continuing to pose uncertainty to the container market," said the company's chairman and chief executive, Sultan Ahmed bin Sulayem,.

"However, the robust financial performance of the first six months also leaves us well placed for 2018 and we expect to see increased contributions from our recent investments in the second half of the year," he said in a statement.

Lower export orders and car sales are likely to slow world trade growth in the third quarter, the World Trade Organization said recently, as a global tariff crusade by Trump to protect American jobs begins to bite.

DP World said it posted a net profit attributable to owners of the company of $593 million in the first half of the year, compared to $606 million during the same period a year earlier.

Cash from operating activities was recorded at $979 million in the first half, slightly lower than $1.0 billion a year earlier.

The port operator said capital expenditure guidance for 2018 remains unchanged at up to $1.4 billion with investments planned in the United Arab Emirates, Posorja (Ecuador), Berbera (Somaliland), Sokhna (Egypt) and London Gateway.

DP World recently won a 30-year concession for the management and development of a port project at Banana in the Democratic Republic of the Congo, which currently has no direct deep-sea port despite being Africa's third-most populous country.

(Reporting by Saeed Azhar; Editing by Adrian Croft) ((Saeed.Azhar@thomsonreuters.com; +971 44536787; Reuters Messaging: saeed.azhar.reuters.com@reuters.net))