(Translated from original letter)

CALVO ENERGÍA, S.A.U.             E15106 CARBALLO – La Coruña – (Spain)

Carballo 1st February 1999

Dear Sir,

On the occasion of having reached 1 operational years of our cogeneration [power] plant, equipped with 2 DEUTZ MWM diesel engines, model 8V 16M-640, producing 6.35 Mwe each, which operate with fuel oil Nº1 and taking into account that we have been using your additivation services from the beginning, we are pleased to reply to your request highlighting the following points:

1.-      During this first year, the 2 engines have been working full-time, without any combustion problem, with fuel oil No. 1 and being additivated with your product "rb bertomeu" beco F1/ASF.

2.-      During the engine's overhauls, we have checked the anti-corrosion effectiveness of the mentioned addtive, since there has been no corrosion in the engines' exhaust valves.

3.-      Similarly, no encrustation has been found in the valves and exhaust gas circuit. No obstructions have been found in the fuel oil circuits. And no problems have been found regarding fuel oil sludge in the storage tanks or in the purifiers.

4.-      The technical service, engine controls and combustion analytics that you have been providing fullfills our expectations when we .

We authorise the use of this letter, for reference purposes.