(Reuters) - Knight Capital Group Inc (NYSE: KCG)  is being forced to raise money after an erroneous trading position wiped out $440 million of its capital, the firm said on Thursday, causing its shares to shed more than half of their value.

Problems at Knight, one of the largest firms that buys and sells stocks to provide liquidity to the markets, emerged at the beginning of trading on Wednesday.

"The company is actively pursuing its strategic and financing alternatives to strengthen its capital base," Knight said in a statement. Knight's shares fell 53 percent to $3.24, hitting an all-time low.

Knight has already approached JPMorgan for emergency funding, according to a report on Fox News. But it was unclear if that funding would be granted. A spokeswoman for JPMorgan declined to comment.

The firm said its broker/dealer divisions would open for business as usual on Thursday, adding that despite the impact of the trading loss, it was in compliance with capital requirements. It also said it had traded out of the entire position.

Wednesday's technology breakdown roiled the prices of some 140 stocks listed on the New York Stock Exchange, undermining fragile investor confidence in the stability of U.S. stock markets.