About 40 percent of Goldman Sachs's loans in the petroleum sector is to oil and gas companies considered "junk" by credit ratings agencies, according to bank data released Monday.

Goldman's overall exposure to oil and gas companies stood at $10.6 billion at the end of 2015, including $4.2 billion to non-investment grade counterparties, the investment bank said in a securities filing.

Of this sum to junk-rated companies, $1.5 billion is in loans outstanding and $2.7 billion in future commitments.

"Significant declines in the price of oil have led to market concerns regarding the creditworthiness of certain companies in the oil and gas industry," Goldman said.

The banking industry's exposure to the oil rout was a major source of worry when large banks reported earnings last month.

Goldman Sachs on January 20 reported 2015 net income of $6.1 billion on $33.8 billion in revenues, which came in 2.1 percent lower than a year ago.