LONDON (Bloomberg) — Rates to ship commodities such as iron ore that have more than doubled this year may stagnate until the middle of May, Greek shipping line Hellenic Carriers Ltd. said.

"If we have no disruptions in South America with strikes, as we did last year, it will help keep rates more or less where they are today for April and perhaps the first half of May," Chief Executive Officer Fotini Karamanlis said in an interview in London.

The Baltic Dry Index, a gauge of commodity-shipping costs, will average 1,786 points in the second quarter, according to the median of 10 estimates compiled by Bloomberg from March 16- 19. That compares with 1,758 points this week. Rates will be checked by fewer shipments of iron ore, the biggest bulk good hauled at sea, the survey showed.

Demand for ore to make steel has weakened after carmakers and other users cut orders in the face of the global economic slowdown. Stockpiles of the metal in China, the biggest user, have risen 8.6 percent this year.

At the same time, Argentine farmers are in a week-long strike against taxes and export restrictions that may cut grain deliveries to ports for shipment overseas. Similar demonstrations took place in 2008.

Hellenic has a fleet of six dry-bulk ships to carry iron ore, grain, steel products and minor bulk cargoes, according to results released by the company on March 16.