Yes, you can use fdi2gds. (Also, most Calibre tools in the last year or two have added native LEF/DEF support. (Calibre xRC has had native LEF/DEF support since 2006 or so.))
fdi2gds is documented in "Translate Third-Party Layout Databases" in the Calibre Verification User's Manual. It lists the supported LEF/DEF versions and any restrictions; this does change, so be sure the manual version matches the version of Calibre you are using.
I tried running fdi2gds by using option -system LEFDEF but it dies out looking for OA libs :
//ERROR: Unable to load OA libraries
What was the command you used? Does your input have OA files as macros? And what version of Calibre is this for?
I asked around, and it seems hierarchical LEF/DEF wasn't supported until version 2011.3 (that's this summer's release -- your company may not have updated to it yet). If you are using a version that only handles flat LEF/DEF and you have hierarchical input, the workaround our AEs use is to individually flatten each child, open the parent in DESIGNrev, and then save as GDS.
If the input is a flat LEF/DEF (or at least does not contain OA macros) and you are getting the error message about libraries, you may have a switch that shouldn't be there, such as -design (only required with OA and Milkyway); or an environment variable such as MGC_CALIBRE_DB_READ_OPTIONS.
Hope this helps-