Bank of Queensland's Tier One capital position was not as strong as senior executives and directors believed last November when shareholders were told that the board had "flexibility to consider capital management options".According to Basel Pillar 3 disclosures made to the ASX on Tuesday, BoQ's Common Tier One capital slumped by almost A$100 million in the three months to the end of November driving its core (CET 1) ratio to 9 per cent from 9.39 per cent at the end of August.The total capital ratio also fell to 12 per cent from 12.4 per cent during the same period as the bank continued to expand lending to government, mortgage and consumer borrowers.At the company's annual meeting on 30 November, managing director Jon Sutton told shareholders that the regulatory capital position was "very strong" and suggested that it would "strengthen" from the 9.39 per cent reported at the end of August."Following APRA's clarity on 'unquestionably strong', we believe we are in a very strong capital position at 9.39 per cent Common Equity Tier 1 as at August 2017," Sutton told shareholders."There are some tailwinds in 2018 which would further strengthen this position by 20 to 25 basis points."This provides us with flexibility to consider capital management options in the future."The slide in the CET 1 ratio wipes out most of the improvement in the key regulatory capital measure that was posted in the 12 months to the end of August last year.It might also mean that BoQ could lose its status as the strongest regional bank in the country (according to the CET 1 benchmark) to Suncorp, which had a ratio of 9.23 per cent at the end of June last year.BoQ's Pillar 3 disclosures indicate that credit quality improved across the bank's lending book in the November quarter.The value of impaired loans at the end of November was steady at $230 million, but the total value of loans past due by 90 days or more declined by $17 million to $460 million.