One of the world’s biggest shipping lines has decided to stop increasing spot freight rates on routes out of Asia to Europe and the U.S. as it sees an end to the rally that has put prices at record highs.

Robust demand for shipping goods across the world’s oceans shows no signs of slowing down, the chief executive of Germany’s largest container carrier said, signaling that elevated rates in the tight market for seaborne cargo may extend into the second half of the year.

Shares of German shipping line Hapag-Lloyd AG plunged as much as 22% after the company cut its profit forecast for the year, as overcapacity in the industry combined with rising fuel costs to put a squeeze on profit.

Steamship line Hapag-Lloyd will increase fees to transport freight to the United States and cross-border freight from Canada. Cargo between Canada and the United States will be subject to a carbon tax.

A merger of German container shipping line Hapag-Lloyd and United Arab Shipping Co. likely will take months to complete, partly due to financing issues blamed on a deep industry downturn, sources familiar with the deal say.

Hapag-Lloyd AG's share price fell the most since its initial public offering in November as a forecast of lower profit and a share-sale plan overshadowed a final deal to join forces with United Arab Shipping Co. to become the world’s fifth-largest container carrier.

Hapag-Lloyd AG approved a plan to acquire all shares of United Arab Shipping Co., paving the way for the second merger in two years to bolster the position of Germany’s biggest container-shipping line in an industry plagued by excess capacity.

Hapag-Lloyd AG, Germany’s top container shipping line, and five Asian carriers will form a new vessel-sharing alliance to take on bigger rivals amid a glut in capacity that’s depressed freight rates.

Hapag-Lloyd is in talks with United Arab Shipping Co. on a possible combination of their container businesses, potentially setting up the German company’s second merger in two years as the maritime-freight industry grapples with a drop in prices.

Hapag-Lloyd, Germany’s biggest shipping line, is seeking to raise $500 million from the sale of new shares this year as it presses ahead with an initial public offering even as the Chinese economic slowdown and a rout in Volkswagen shares sparked turmoil on stock markets.