About 10 of the 19 largest US banks being stress tested will be instructed by regulators to raise more capital, according to a source familiar with official talks.

The banks have been negotiating with their regulators about the depth of their capital needs, should the recession prove to be deeper and longer than anticipated. Markets have been anxiously anticipating the results, which will differentiate the strongest banks from those still expected to sustain considerable credit losses.

The exact roster of banks needing to build their capital positions is still unclear. Banks are expected to be briefed on the official results today. The Federal Reserve and Treasury Department will also tell them how policymakers plan to publicly unveil the market-sensitive results, the source said, speaking anonymously because the discussions are private.