We are not aware of any programs that convert IBES SIGC to SIC.
As stated in the IBES Glossary, the SIGC is a proprietary scheme based on S&P500 Industry Grouping and Morgan Stanley Capital International Industry Classifications, so we believe it would be non-trivial to convert SIGC to SIC:
"I/B/E/S currently uses a proprietary classification scheme to categorize companies into homogenous groups according to business lines. In the United States, a scheme similar to the S&P 500 Industry groupings is followed. The principal differences between the two are the result of new grouping being added to I/B/E/S in an effort to accommodate a larger, more diverse universe. For non-US companies, a system loosely based on the Morgan Stanley Capital International Industry Classifications is used. Once again, the fact that the I/B/E/S universe is considerably larger than the MSCI index necessitates additional industry groups."
One brute-force method you can use to give you a rough SIC-> SIGC translation follows:
- Find companies in your SIC Codes of interest (using CRSP or Compustat to find SIC->Tickers).
- Go to IBES and find the SIGC associated with those tickers (Tickers->SIGC).
- Do some statistical analysis to see which SIGC occurs most often for your SIC codes.