(Bloomberg) — Avance Gas Holding Ltd., whose largest shareholder is Norwegian shipping billionaire John Fredriksen, said it has agreed to sell its entire fleet of very large gas carriers to BW LPG Ltd.

Under the deal, BW will acquire the vessels for a total consideration of just over $1 billion, the companies said in a statement. The deal makes Avance BW’s second-largest shareholder, owning nearly 13 percent. Avance’s shares rose sharply while BW’s fell.

Very large gas tankers are the largest ships for transporting liquefied gases such as propane and butane, but in the future they may also be used to transport ammonia.

Revenues in the sector have soared in recent years following a surge in U.S. exports of liquefied natural gas and huge Chinese purchases, exacerbated by the disruption of the Panama Canal.

However, this boom has now cooled down as order books for such vessels have exploded. One reason for this is shipowners’ assumption that ammonia will be a widely used marine fuel in the coming decades.

“The acquired vessels will further increase our commercial scale and increase our operating leverage in a market that we expect to be strong in the coming years, thereby consolidating earnings and dividend potential,” said Kristian Sorensen, Chief Executive Officer of BW LPG.

Avance shares rose as much as 11% in Oslo before paring gains. BW shares fell as much as 3.1% before paring losses.

The deal will expand BW’s VLGC fleet, which is already the largest in the world.