An MPEG-SAOC audio signal decoder (100; 420) for providing an upmix signal representation (130; 484a to 484M) on the basis of a downmix signal representation (110; 430) and an object-related parametric information (112; 432), and depending on a rendering information (120; 482), the apparatus comprising: an object parameter determinator (140; 464, 468, 474) configured to obtain inter-object-correlation values for a plurality of pairs of audio objects, wherein the object parameter determinator is configured to evaluate a bitstream signaling parameter in order to decide whether to evaluate individual inter-object-correlation bitstream parameter values, to obtain inter-object-correlation values for a plurality of pairs of related audio objects, or to obtain inter-object-correlation values for a plurality of pairs of related audio objects using a time/frequency dependent common inter-object-correlation bitstream parameter value; and a signal processor (150; 480) configured to obtain the upmix signal representation on the basis of the downmix signal representation and using the inter-object-correlation values for a plurality of pairs of related audio objects and the rendering information; wherein the audio signal decoder is configured to combine an inter-object-correlation value IOC i,j associated with a pair of related audio objects with an object level difference value OLD i describing an object level of a first audio object of the pair of related audio objects and with an object level difference value OLD j describing an object level of a second audio object of the pair of related audio objects, to obtain a covariance value e i,j associated with the pair of related audio objects; wherein the audio decoder is configured to obtain an element e i,j of a covariance matrix according to e i, j = OLD i OLD j IOC i, j; wherein the object-related parametric information (112;432) comprises the bitstream signaling parameter and either the individual inter-object-correlation bitstream parameter values or the time/frequency dependent common inter-object-correlation bitstream parameter value. an object parameter determinator (140; 464, 468, 474) configured to obtain inter-object-correlation values for a plurality of pairs of audio objects, wherein the object parameter determinator is configured to evaluate a bitstream signaling parameter in order to decide whether to evaluate individual inter-object-correlation bitstream parameter values, to obtain inter-object-correlation values for a plurality of pairs of related audio objects, or to obtain inter-object-correlation values for a plurality of pairs of related audio objects using a time/frequency dependent common inter-object-correlation bitstream parameter value; and a signal processor (150; 480) configured to obtain the upmix signal representation on the basis of the downmix signal representation and using the inter-object-correlation values for a plurality of pairs of related audio objects and the rendering information; wherein the audio signal decoder is configured to combine an inter-object-correlation value IOC i,j associated with a pair of related audio objects with an object level difference value OLD i describing an object level of a first audio object of the pair of related audio objects and with an object level difference value OLD j describing an object level of a second audio object of the pair of related audio objects, to obtain a covariance value e i,j associated with the pair of related audio objects; wherein the audio decoder is configured to obtain an element e i,j of a covariance matrix according to e i, j = OLD i OLD j IOC i, j; wherein the object-related parametric information (112;432) comprises the bitstream signaling parameter and either the individual inter-object-correlation bitstream parameter values or the time/frequency dependent common inter-object-correlation bitstream parameter value.