THE state government's forestry agency broke logging rules at least 634 times in the last financial year, according to data gathered by the NSW Environment Protection Authority.

The environmental investigator visited 39 logging sites all around NSW, recording an average of 16 breaches of licence rules for each visit.

Despite the flood of breaches, only 17 warning letters and 10 penalty notices were issued to the state's forestry agency, Forests NSW.

The EPA said the small proportion of penalties it had imposed reflected the fact it had dealt with many of the breaches by ''guidance, education and discussion with Forests NSW''.

But conservation groups claim the statistic shows the EPA's strike rate in enforcing bad logging practices is pathetic.