Production issue -- FI Doc Exceed 999 lines

Hi Experts..

we are facing one problem when we are doing GR, the FI documents if more than 999 line items it is not going to generate any FI documents... we have 1000's of line items in the same GR....

NOTE: in Development it is generating new documnet for the above 999 lines.... in production it is not genarating any document if exceeds 999 lines.. system trowing an error " maximum number of items in FI reached"

Kindly help me in resolving this issue... very critical for us

Thanks in advance

Alex