When running this script, I get:

SET @WorkSheet=NULL; SELECT @WorkSheet=CAST(BulkColumn as xml) FROM OPENROWSET (BULK 'M:\HTS\Export\currency.xls', SINGLE_BLOB ) A;

XML parsing: line 0, character 0, unrecognized input signature at line 1

Msg 50000, Level 16, State 1, Procedure uspImportExcelSheet, Line 497

XML parsing: line 0, character 0, unrecognized input signature

Tried a few xls files, all gave the same error.