LONDON - The BP PLC (BP) liquefied natural gas tanker British Innovator berthed at the U.K.'s Isle of Grain terminal Thursday, terminal operator National Grid PLC (NGG) said in a statement.

The ship is capable of holding 138,286 cubic meters of LNG. Two U.K.-based gas traders said it will probably begin discharging its cargo Friday and will boost already ample supplies into the U.K. gas market.

"I expect Grain to keep discharging (gas) at 13 million cubic meters a day today to get tanks empty to accommodate that cargo," said a gas trader at a U.K. utility.

The price of gas for delivery within-day has fallen 9.5% since the beginning of the week to 45.3 pence a therm due to mild weather and healthy imports from Norwegian pipelines, the trader said.

The lower gas price has made the U.K. a less attractive destination for LNG cargoes compared with Asia, where prices have been pushed up because demand has been strong due in part to the shutdown of a large nuclear power plant in Japan.

The U.K. and continental Europe still offer exporters in the Middle East, North Africa and the Caribbean a premium of $2-3 per million British thermal units over the U.S., where mild weather and record high storage levels have depressed prices, according to data published by LNG Intelligence.

The Isle of Grain terminal is operated by National Grid PLC (NGG) and is able to import 4.4 billion cubic meters of gas a year. BP and Algerian state energy company Sonatrach are the sole capacity holders at the terminal.