According to some scholars, there would be no problem to take such interest if it is given under a valid legal contracts like Mudärabah (A contract, entered into by two persons on the condition that the stock or Rãs al-Mãl in trade shall belong to one of them, and the labor to another, and in case profit is accrued, it should be divided between both of them.  If the whole profit is stipulated to go to the proprietor (of the stock) it is called “Bida’ah, Hibah (donation) moawaddah (exchange contract), advocacy for business or Musharakat (partnership).    According to other scholars, it is an example of haram usury.
 
Appendix:  The grand maraja’ answer to this question is as follows: [1]
Grand Ayatollah Khamenei (May Allah grant him long life):  There is no problem in it if it is done under moawaddah contract or the like.  If you lend it, you are not allowed to take this interest.
Grand Ayatollah Safi Golpayegani (May Allah grant him long life):  It is impermissible to take interest if you stipulate a condition by which they have to pay back its interest.  If they themselves give you the interest there would be no problem to take it.
Grand Ayatollah Makarem Shirazi (May Allah grant him long life):  Given the supposition made in the questions, taking this interest is considered as haram.
Grand Ayatollah Makarem Shirazi (May Allah grant him long life):  It is considered as a haram act if it is not done under any kind of valid Islamic contracts like Mudarabah and the like.

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