UPDATE 1-S&P offers rare defense of Lehman 'A' rating

In commentary published that day, S&P said it believed the bank's ratings could be affirmed if it succeeded in carrying out those actions, although it cautioned that failure could lead to a multi-notch downgrade.

But Lehman's share price continued to slide and ended the week down more than 80 percent.

Heading into a round of talks that weekend, Lehman had excess liquidity of $42 billion at the holding company level and enough liquidity to cover short-term funding needs, said Sprinzen.

However, "facing a likely complete collapse in confidence on the part of creditors, counterparties, and customers when it opened for business on Monday, Sept. 15," the company filed for bankruptcy protection. (Reporting by Ciara Linnane; Editing by Dan Grebler)