A method for the production of urea-melamine-formaldehyde resin, characterized by a stepwise condensation of urea with formaldehyde to a prepolymer carried out before performing a co-condensation reaction with melamine, said stepwise condensation comprising the steps: (a) providing an urea-formaldehyde concentrate; (b) adding urea to the urea-formaldehyde concentrate of the step (a) and performing a first urea-formaldehyde-condensation reaction at a pH between 5.6 and 9.0, and at a temperature below 80°C; (c) adding urea to the reaction products of said first urea-formaldehyde-condensation reaction to reach formaldehyde: urea mol ratio of from 1.5:1.0 to 2.5:1.0, an amount of urea added at this step being equal to the amount of urea added at the step (b) to the urea-formaldehyde concentrate (LTFC) of the step (a), followed by agitating the mixture at a temperature less than 70°C; (d) heating the mixture of the step (c) to a temperature of 80 to 100°C under agitation and performing a second urea-formaldehyde-condensation reaction at a pH of 3.0 to 5.5, then ageing the mixture; (e) raising the pH of the reaction products of said second urea-formaldehyde-condensation reaction to 9.0-10.0 and adding melamine in the amount of 0.04-0.25 mol melamine per 1 mol of urea; (f) performing melamine-formaldehyde-condensation reaction at a pH of 9.0 to 10.0 and at a temperature of 80 to 88°C; (g) adjusting the temperature of the reaction mixture of the step (f) to a temperature of 50 to 80°C, and adding urea and optionally further formaldehyde as the composition comprising formaldehyde of the step (a) to the reaction products of said melamine-formaldehyde-condensation reaction, cooled previously, thus reaching formaldehyde: urea mol ratio equal to (1.1-1.2):1; and (h) performing a third urea-formaldehyde-condensation reaction at a temperature of 65 to 70°C with agitating and then cooling the reaction mixture to 25-30°C. (a) providing an urea-formaldehyde concentrate; (b) adding urea to the urea-formaldehyde concentrate of the step (a) and performing a first urea-formaldehyde-condensation reaction at a pH between 5.6 and 9.0, and at a temperature below 80°C; (c) adding urea to the reaction products of said first urea-formaldehyde-condensation reaction to reach formaldehyde: urea mol ratio of from 1.5:1.0 to 2.5:1.0, an amount of urea added at this step being equal to the amount of urea added at the step (b) to the urea-formaldehyde concentrate (LTFC) of the step (a), followed by agitating the mixture at a temperature less than 70°C; (d) heating the mixture of the step (c) to a temperature of 80 to 100°C under agitation and performing a second urea-formaldehyde-condensation reaction at a pH of 3.0 to 5.5, then ageing the mixture; (e) raising the pH of the reaction products of said second urea-formaldehyde-condensation reaction to 9.0-10.0 and adding melamine in the amount of 0.04-0.25 mol melamine per 1 mol of urea; (f) performing melamine-formaldehyde-condensation reaction at a pH of 9.0 to 10.0 and at a temperature of 80 to 88°C; (g) adjusting the temperature of the reaction mixture of the step (f) to a temperature of 50 to 80°C, and adding urea and optionally further formaldehyde as the composition comprising formaldehyde of the step (a) to the reaction products of said melamine-formaldehyde-condensation reaction, cooled previously, thus reaching formaldehyde: urea mol ratio equal to (1.1-1.2):1; and (h) performing a third urea-formaldehyde-condensation reaction at a temperature of 65 to 70°C with agitating and then cooling the reaction mixture to 25-30°C.