TUNIS (Reuters) - The African Development Bank (AFDB) will lend Tunisia between $1.5 billion and $2 billion over the next five years, the bank's North Africa director Jacob Kolster said on Wednesday. Kolster announced the loan at an investment conference in Tunis at which regional and Western partners have pledged billions in financial assistance to shore up Tunisia's struggling economy. (Reporting by Tarek Amara; Writing by Aidan Lewis; Editing by Catherine Evans)