From The Hacker's Guide:

"SYLK is limited to 9,999 records while APPENDing ... WK1, WKS, WR1 and WRK formats are limited to 8,192 rows."

It isn't trying to be comprehensive about this and doesn't give a limit for .XLS but I suppose the limit could be something like these other numbers.

>I *think* that the limit with COPY TO is more severe than this. I believe it's 8192 or 16384 rows.
>
>>I must agree that I love using OLE Automation for writing any data at all to excel due to the control it gives you. However, on your point, excel only allows 65,536 rows so if COPY TO limits you to 65,000 you really haven't lost anything.