NEW YORK (CNBC) — Stocks accelerated their selloff to trade near session lows Wednesday as worsening fears over the euro zone crisis rattled investor sentiment.

The Dow Jones Industrial Average tanked over 400 points, led by Hewlett-Packard and JPMorgan.

The S&P 500 and the Nasdaq also declined sharply. The CBOE Volatility Index, widely considered the best gauge of fear in the market, surged near 34.

All 10 S&P sectors were firmly in negative territory, led by banks and materials.

Stocks slumped further after the Greek President called for a meeting of political leaders on Thursday after the nation’s two main political parties failed to agree on who will lead the country’s interim government.

Earlier, Reuters reported that Greek party leaders had agreed on house speaker Filippos Petsalnikos to head Greece’s new coalition government, but the decision may have been withdrawn.

In addition, EU officials said they have no plans in place for a financial rescue of Italy, and adding the euro zone was not even considering extending a precautionary credit line to Rome.

Full story: Dow slides more than 400 points on European fears