OTS spreadsheet templates may be used as a basis of creating various spreadsheet formats, including XLS. Just not all formatting may be transported flawlessly, as OTS is used in the open source office bundles like LibreOffice Calc or OpenOffice.org.
Convert OpenOffice.org OpenDocument spreadsheet template to Microsoft Excel 97 to 2003 workbook.
We found 3 software records in the database related to .ots to .xls file format conversion.
Apple macOS / Mac OS X software - convert ots to xls on OS X
A full-featured set of office applications for Mac OS X
Convert from ots file format
The tables with software actions are a good pointer for what a certain program does with various file types and often may give users a good hint how to perform certain file conversion, for example the above-mentioned ots to xls. However, it is not perfect and sometimes can show results which are not really usable because of how certain programs work with files and the possible conversion is thus actually not possible at all.
Multiplatform software - convert ots to xls on any platform
Full-featured spreadsheet tool from LibreOffice suite
Spreadsheet program from OpenOffice.org productivity suite