Shares of insurers fell Friday along with the broader market amid continuing concern about the financial stability of mortgage giants Fannie Mae and Freddie Mac.

Shares of insurers fell early Friday as the broader market plunged amid fears Fannie Mae and Freddie Mac, the nation's largest purchasers of mortgages, would need a government bailout.

The week started and finished with news of the nationalization of British troubled bank Northern Rock, ending a five-month period of uncertainty about the bank’s future. In between, results from banks caused investors ecstasy or agony.

Dutch financial services group ING took a lower than expected impairment charge on its riskier investments in its fourth-quarter results and its risk exposure is limited, CFO John Hele told CNBC Europe on Wednesday.

The fate of European stocks rests with banks next week, as big financial institutions are due to report earnings and investors will remain very nervous about the health of the sector, analysts said on Friday.

Banks are a good long-term investment, but in the short and probably medium term fears of further writedowns will still send shockwaves through the market, analysts said on Tuesday.

Shares in Dutch banking group ING fell by as much as 6.5 percent on Tuesday on market talk of large writedowns, traders said.