Some 37 very large gas carriers (VLGCs) of a total capacity of 3.1 million cbm are to be delivered this year, resulting in a 23% fleet growth in terms of capacity, according to shipping brokerage Banchero Costa Research.

23 vessels of all sizes were delivered in the first four months of 2015, including seven VLGCs, or vessels of more than 70,000cbm, the report shows.

Another 45 VLGCs, or 3.8 million cbm, are slated for delivery in 2016, adding up to an additional 22% global fleet growth.

The brokerage estimates that as of May 2015, there are 170 VLGCs aged from up to four years to 30 years serving the market.

The vessel shortage that has seen kept rates strong throughout 2015 are expected to ease out with the inflow of the new ships.

"In the first four months of 2015 we have seen increased volatility in the LPG spot market continuing, including a short recovery in late February,"Banchero Costa said.

"Timecharter rates of VLGCs have continued to increase, reflecting the improving market. On the other hand, timecharter rates for smaller units have remained under pressure," the report added.