I. INTRODUCTION Multiferroics are materials, in which at least two types of order coexist. For example, (anti)ferroelectricity and (anti)ferromagnetism can take place simultaneously [1, 2]. Multi- ferroicity of frustrated magnets, in which magnetism and ferroelectricity coexist with gigantic magnetoelectric coupling, has attracted an interest due to challenges to many-body theory, as well as by discoveries of new phenomena with a promice for potential applications as transducers, actuators, and sensors [3–5]. Quite a few of these multiferroics are manganites, in which the magnitude of the spin of the Mn +3 ion is large and hence may be treated semiclassically. The perovskites like AMnO$_{3}$ has been widely studied in this context due to the coexistence of ferroelectric and magnetic order in some of them [6–8]. In BiMnO$_{3}$ the nature of the A 3+ ion is central to determine the structural, ferroelectric, and magnetic properties of this system [9]. With the help of first principle calculations, Hill et al. [10] provided the reasons why we observe so few ferroelectric magnets and predicted the existence of ferroelectricity in BiMnO$_{3}$. In ferroelectrics such as SrTiO$_{3}$ it is usually driven by a hybridization of empty 3 d 0 transition metal orbitals with occupied 2 p orbitals of the octahedrally coordinated oxygen ions. The appearance of magnetic moment in turn, requires partial occupancy of the 3 d orbitals. So, in materials such as BiMnO$_{3}$, the coexistence of Mn 3+ ions (3 d 4 configuration) with 6 s 2 lone electron pairs due to the Bi 3+ ions can lead to the coexistence of magnetic order with electric polarization at low temperature [11]. BiMnO$_{3}$ has been the subject of considerable interest, mainly due to its structural sim- plicity. From magnetic point of view, Mn 3+ ion in this case has magnetic moment of 3 . 6 µ$_{B}$ , a value close to ground-state 4 µ$_{B}$ , induced by the Hund’s rule coupling. In the octahedral environment the electronic configuration is t 3 2 $_{g}$e 1 $_{g}$. From electrical point of view BiMnO$_{3}$ is an insulator [12]. A detailed structural study of BiMnO$_{3}$ suggests [13, 14] that the material has a highly distorted perovskite structure (centrosymmetric space group C2/c) which is incompatible with the existence of ferroelectricity. In spite of this, there is an experimental evidence of ferroelectric order in a BiMnO$_{3}$ polycristaline samples [13, 15, 16]. The discussion concerning the origin of the ferroelectricity in this compound is still controversial. We present a simple phenomenological approach useful in describing systems like BiMnO$_{3}$ 2