Wall Street flat after opening

US stocks were flat in early trading Monday as investors remained cautious while they waited to see whether ailing bond insurer Ambac Financial Group Inc. gets a capital injection.

Investors were also awaiting a fresh update on the troubled housing sector as the government is due to release a report on January existing-home sales later Monday.

There has been speculation that Ambac might find sufficient capital early this week to hold onto the stellar "AAA" rating it needs to remain in the municipal bond business. However, there was no confirmation that this was the case and the uncertainty began to gnaw at investors.

The Dow Jones industrial average fell 4.07, or 0.03 percent, to 12,376.95.

Broader stock indexes also dipped. The Standard & Poor's 500 index fell 1.62, or 0.12 percent, to 1,351.49; and the Nasdaq composite index dropped 1.20, or 0.05 percent, to 2,305.15.

(Agencies)