Stored procedure msdb.dbo.sp_reassign_dtspackageowner can be used to change the owner of a DTS package but MS has hard-code logic to restrict the usage only to the current package owner or a sysadmin .
Suggest creating a new procedure based on sp_reassign_dtspackageowner but that does not include the hard-coded security logic and then grant execute rights appropriately.
These are the SQL statements that need to be excluded:
IF (ISNULL(IS_SRVROLEMEMBER(N'sysadmin'), 0) <> 1)
IF (NOT EXISTS (SELECT * FROM sysdtspackages WHERE id = @id AND owner_sid = SUSER_SID()))
SELECT @name = name FROM sysdtspackages WHERE id = @id
RAISERROR (14585, -1, -1, @name)
RETURN(1) -- Failure
SQL = Scarcely Qualifies as a Language