Mr. A signed a one (1)-year contract with XYZ Recruitment Co. for deployment as welding supervisor for DEF, Inc. located in Dubai. The employment contract, which the POEA approved, stipulated a salary of US$600.00 a month.

Mr. A had only been in his job in Dubai for 6 months when DEF, Inc. announced that it was suffering from severe financial losses and thus intended to retrench some of its workers, among them Mr. A. DEF, Inc. hinted, however, that employees who would accept a lower salary could be retained. Together with some other Filipino workers, Mr. A agreed to a reduced salary of US$400.00 a month and thus, continued with his employment.

Was the reduction of Mr. A's salary valid? Explain. (2019 BAR)