The FTSE 250-listed firm said its average production for the first half of the year fell 21 per cent from 42.8 thousand barrels of oil equivalent (kboepd) in 2010 to 36.6 kboepd.
Despite good production performance from the Anoa field in Indonesia, the Edinburgh-based explorer said production took a hit after the unexpected shutdown of its Balmoral field in the North Sea together with maintenance work at Wytch Farm.
The group also warned that its Huntington development in the North Sea is likely to be delayed.
As a result Premier Oil has downgraded its production target for the year to a range of 40 and 45 kboepd, down from its earlier 45 kboepd guidance stated in May.
“With continuing good progress on our Asian development projects we expect to see a significant increase in production to around 60 kboepd by year end,” Simon Lockett, chief executive said.
Shares in Premier Oil fell 20.70p closing at 414.10p last night.