NEW YORK ( TheStreet) -- Financial stocks struggled this week as investors scurried away from the sector over continued fears of mortgage loss and put-back exposure at the banks as well as global economic concerns. The Financial Select Sector SPDR ( XLF)ended the week down 4% to $14.94. Regulators, bank executives, political consultants and other industry observers gathered at the Securities Industry and Financial Markets Association's (SIFMA) annual meeting in New York City on Monday. Among the speakers, Securities and Exchange Commission Chairwoman Mary Shapiro said during a presentation that she is working to correct "light of touch" regulatory tendencies that existed at her agency before the crisis erupted. Shapiro also said that, among other things, Wall Street compensation is at the top of the regulator's list going forward. > > Bull or Bear? Vote in Our Poll Monoline and mortgage insurers were in the spotlight this week. Ambac Financial Group ( ABK) filed for Chapter 11 bankruptcy on Monday, one week after announcing it would miss an interest payment on a portion of its outstanding debt. Also, Assurant ( AIZ) shares plummeted this week after questions were raised concerning the ethics of the forced-placed insurance business.Additionally, reports surfaced that Bank of America ( BAC) was suing Old Republic Insurance, a subsidiary of Old Republic International ( ORI). The nation's largest institution is claiming that the mortgage insurer is unnecessarily denying claims on defaulted mortgages put forth by BofA. Other news this week in the financial sector included the much talked about sale of BlackRock ( BLK) shares by two of its largest investors, Bank of America and PNC Financial Services ( PNC). BlackRock shares were priced at $163 in the secondary offering. Bank of America said Friday it was selling additional Blackrock shares it owns to Mizuho Financial ( MFG). Separately, Morgan Stanley ( MS) stands in position to make $664 million gross profit off the sale of investment management firm Invesco ( IVZ) shares it gained in June, it said this week. Insurance giant Prudential ( PRU) also priced a $1 billion common stock offering on Friday to fund its acquisitions of AIG's Japanese life insurance units. --Written by Laurie Kulikowski in New York. To contact the writer of this article, click here: Laurie Kulikowski. To submit a news tip, send an email to: firstname.lastname@example.org.