The Reserve Bank has said about 36% of the overall 4.1% bad assets in the system have been created by six sectors of the economy - infrastructure, metals, textiles, chemicals, engineering and mining.
These sectors, though, have only 30% of the credit share.
The central bank, in its annual report for FY2013-14, said gross non-performing assets in the system have grown to 4.1% in FY'14 from 3.4% a year ago.
It also said the contribution of mandatory priority sector loans to the overall bad assets have come down during the last fiscal.
Stating that the state-run banks are the chief sources of stress, RBI said these six specifically identified sectors of infrastructure, metals and products, textiles, chemical and chemical products, engineering industries and mining and quarrying alone contributed 36% of gross NPAs, as against their 30% contribution to total advances.
The gross non-performing assets ratio for the non-priority sector grew to 4% as of March 2014 as against 3% in the year ago period, while the same for priority sector stood stable at 4.4%, it said.
"The non-priority sector has contributed more in the deterioration of the loan asset quality of the banking sector in recent years," it said, adding that the contribution of PSL loans to the overall bad loans narrowed to 36% as of FY'14 from 40% in FY'13.
Commenting on the health of the sector, the RBI said it "remains satisfactory".
On reports of some improvement shown by the banks in the asset quality in the fourth quarter, the RBI hinted at there not being a cause for celebration yet, as this was due to the asset sales to ARCs.
Additionally, it also highlighted the lurking threat, pointing out at the high growth in restructured assets during the previous fiscal 2012-13. It said the asset sales by all banks rose to Rs 127.1 billion in the March quarter, as against Rs 35.7 billion in the previous quarter and Rs 6 billion in the quarter before.
In the overall asset quality stress scenario, gross NPAs at the state-run lenders rose to 4.7% as against 3.8% in the year ago period, while foreign banks also showed a rise in NPAs to 3.9% from 3%.
Private sector banks provided some relief despite the overall gloomy business climate, with their gross NPAs being stable at 1.9%, the RBI said.
Bankers attribute the rise in bad assets to the sagging economic growth, coupled with other difficulties like a sense of 'policy paralysis' wherein decisions got stuck impacting projects, and also due to some judicial interventions.
In the financial stability report released December last year, the RBI had estimated that gross NPAs increase to a peak of 4.6% in September 2014, (from 4.2% in September 2013) and then improve to 4.4% in March 2015.
Lending to the retail sector was the succour to the banks during this time, and the RBI annual report also cemented this point with data pointing to an increase in credit, coupled with a decline in NPAs.
There was a marginal increase in share of retail credit to 19% of gross credit as of March 2014, but gross NPAs from this portfolio declined to 2% from 2.3% in FY'13, the RBI said.