Container shipping lines have agreed to raise Asia-US freight rates by $300 per 40-ft FEU to West Coast ports and by $400 to all other ports in the US from May 15 while Maersk Line and CMA-CMG said they would raise prices prices by an average $500 per TEU over the next eight days on the Asia-Europe route.

The Asia-US increase was agreed by companies in the Transpacific Stabilisation Agreement (TSA), which also adopted a $400 per FEU peak season surcharge effective June 15, reported Reuters.

The TSA groups 15 of the world's biggest container shipping lines, including Denmark's Maersk Line, a unit of A P Moller-Maersk, privately owned Swiss-based Mediterranean Shipping Co (MSC), French privately held CMA CGM, China's Cosco and South Korea's Hanjin Shipping.

The container shipping industry was hit hard by the global economic downturn since 2008 and only a few lines made a profit in 2013 due to supply outstripping demand.

Spot freight rates are calculated and published every week by Shanghai Shipping Exchange and the surcharges added to that.

Last week rates for transport from Asia to the US West Coast stood at $3,844 per 40-foot container and $6,656 to ports on the East Coast.

"Carriers are continuing to play catch-up on rates, which have been effectively stagnant since 2011," TSA executive administrator Brian Conrad said.

Transpacific container lines are experiencing a surge in eastbound bookings that began in January and is expected to continue into the second half of 2014, with vessel utilisation in the mid-90 percent range via the West Coast and in the high-90 percent to full range to the East and Gulf Coasts, the TSA says.

Meanwhile, Maersk Line and CMA-CMG said they are increasing their official prices by an average $500 a standard container over the next eight days, on the Asia-Europe route, reported Dow Jones Newswires.

The move came after rising demand pushed up the Shanghai Containerisation Freight Index by $221 a container, to $1,305. The index is a benchmark for prices for a typical Shanghai-Rotterdam sailing.

That index is still down 23 percent since the start of the year, despite two earlier increases by shippers in January and April. Those increases didn't last. Smaller competitors quickly undercut the increases by the bigger shippers.

What is different this time around? Asian exports to Western markets are higher as the global economic recovery gains strength.

"Things are generally looking up, with consumer confidence at its highest level since 2008 in both Europe and the US," said Jonathan Roach, a senior container analyst at London-based Braemar Seascope.

This week, Moody's Investors Service upgraded its outlook for the global shipping industry to stable from negative. That was the first such upgrade since 2011. The ratings company cited improved earnings, driven by lower fuel costs, increased ship-scrapping levels and a slowdown in new ship deliveries.

Still, container shipping remains plagued by overcapacity after record orders of new vessels in 2007, just before the financial crisis triggered a plunge in global trade.

"The fundamental problem of way more tonnage in the water than what's needed is still there," said Lars Jensen, chief executive of SeaIntel Maritime Analysis in Copenhagen. But he said he expects big players like Maersk, CMA CGM and MSC, will have more control over freight rates eventually.

The three companies are in the process of winning regulatory approval for a ship- and route-sharing alliance called the P3. If approved, the three partners will control around 40 percent of capacity along major trade routes.