The ratio of non-performing loans to total outstanding loans held by Spanish banks has risen to a record 9.42 percent, topping the previous mark of 9.15 percent set in February 1994.

According to data published Friday by the Bank of Spain, the total value of the banks' bad loans rose in June to 164.36 billion euros ($202.2 billion), compared to a total loan portfolio of 1.74 trillion euros ($2.14 trillion).

The bad-debt ratio climbed uninterruptedly between June 2011 and June 2012, increasing by 273 basis points over that 12-month period from 6.69 percent to 9.42 percent.

In terms of the total value of the banks' bad loans - those overdue by at least three months - that amount rose in one year from 121.62 billion euros ($149.63 billion) to 164.36 billion euros ($202.2 billion).

Numerous Spanish banks are battling to stay afloat after the bursting of a long-building property bubble left them saddled with too many non-performing loans.

A euro-zone bailout of those ailing institutions was approved this summer, with up to 100 billion euros ($123.2 billion) to be disbursed over an 18-month period.

A Eurogroup memorandum of understanding on the aid package, dated July 9, said a "key component of the program is an overhaul of the weak segments of the Spanish financial sector".