[Pavel M.]

такой вариант не подойдет

<style type='text/css'>
.wrap {
    height:300px; 
    width:300px; 
    position:relative; 
    border: 1px solid;
}
.top {
    height: 50px;
    background: #eee;
        
}
.center {
    position:absolute;
    width: 100%;
    left: 0; 
    top: 50px; 
    bottom: 40px;
    background: #00f;
}
.bottom {
    position: absolute;
    width: 100%;
    left: 0; 
    bottom: 0;
    height: 40px;
    background: #f00;
}
</style>
  
<div class=wrap>
	<div class=top>123</div> 
	<div class=center>456</div>
	<div class=bottom>789</div>
</div>