UPDATE 1-Hunting sees impact from lower margins, U.S. decline

* Hunting reports 40 pct decline in U.S. rig activity

* Acquires National Coupling Company for $55 mln cash

* Shares fall 1.9 pct

(Adds detail, share price)

LONDON, April 22 (Reuters) - Energy services company Hunting Plc (HTG.L) said on Wednesday a rapid decline in its U.S. activities, mainly gas drilling, and reduced margins would impact the group in the months ahead.

Hunting said U.S. rig activity fell 40 percent in the first quarter on lower demand. However, its performance in the Middle East and South East Asia offset these declines and trading from January to March was in line with the board's expectations.

"Recovery in the US will ultimately depend on a rebound in natural gas prices," it said ahead of its AGM later on Wednesday.

"With lower industrial demand due to the recession, coupled with high storage levels, a recovery in gas drilling appears unlikely in the short term."

Hunting also announced the acquisition of privately owned National Coupling Company Inc, a developer and manufacturer of subsea hydraulic equipment, for $55 million in cash. The purchase is expected to enhance earnings in 2009, it added.

The company said it identified several acquisition opportunities and planned to make further purchases using proceeds from the sale last December of its Canadian oil and gas division, Gibson Energy, which raised 517 million pounds ($750 million).

Shares in Hunting fell 1.9 percent to 391.75 pence by 0730 GMT.

(Reporting by Kylie MacLellan; Editing by Julie Crust)