Ambac Financial Group Inc., the bond insurer, has posted a net income during the fourth-quarter. This information was given on Thursday and because of the news, the share price of the company went up by 71 per cent during the trading session on Friday.

The Q4 net income of company was $558.1 million after posting a loss of $2.34 billion during the same period last year. This means per share the profit of Ambac was $1.93 against a loss of $8.14 last year.

Tax benefits to the tune of $472 million are the reason for this profit. Besides, it has also managed to curb down its costs mainly in the consuming financial-guarantee business.

Meanwhile, Ambac also reported a total net loss of $385.4 million in 2009 Q4, which is much lesser than the $916.4 million figure for last year.

After the sub-prime crisis the business of one of the world's largest bond insurer has been hit hard because of its repayment of claims. After that, the regulator of Ambac's bond insurance business, Wisconsin's Office of the Commissioner of Insurance took away a big part of its business.