UPDATE 1-Oil Search says its H1 revenue falls 18 pct after PNG quake

* Australian company is focused on Papua New Guinea

* Revenue hit by February quake in region

* Company in discussions over further LNG projects in PNG (Adds detail, background)

July 17 (Reuters) - Australia’s Oil Search Ltd reported an 18 percent fall in first half revenue on Tuesday, hit by lower output at a key liquefied natural gas (LNG) project in Papua New Guinea after a major earthquake in the region in February.

Revenue dropped to $557.8 million in the six months to June from $676.2 million a year earlier, the company said.

Half-year sales volumes declined 31 percent to 9.77 million barrels of oil equivalent (mmboe) from the first half of last year.

Oil Search’s managing director, Peter Botten, said in a statement the company was in discussions over further LNG developments in Papua New Guinea.

The oil and gas explorer said production at the Papua site, known as PNG LNG, was heading towards the upper end of downgraded guidance of 23-26 mmboe for 2018.

Oil Search had revised 2018 unit production costs and production guidance earlier this year after a devastating earthquake in Papua New Guinea energy-rich interior, forced ExxonMobil to shut down operations.

Production resumed in the second week of April, a fortnight ahead of schedule. (Reporting by Aditya Soni in Bengaluru Editing by Paul Tait and Joseph Radford)