The article has described the 'correlation' in the Russian Federation (RF) between credit-limit (CL) size and use of the interbank lending market, highlighting the conditions in St. Petersburg (SPb). It notes in so doing that the Russian market offers personalized bank credit (lending) operations. The document subsequently analyzes whether the interbank tie-up to its counter-party financial source (bank) has a 'duration-oriented сorrelation' with the CL size. The report bases the CL analysis on an empirical research base provided by a SPb bank. Containing a sample with 1702 'firm-month factors' (affecting CL), the analysis revealed that a correlation does in fact exist in the RF between CL size and credit longevity (in interbank marketplace). The blueprint has suggested in closing that other bank features -profitability, capital adequacy, credit activity and asset quality - also might be related to CL size.