The New York Stock Exchange said Monday that it will add at least 31 stocks to the list of 799 affected by the Securities and Exchange Commission's temporary ban on short selling outlined last week. All of the companies have financial-services operations, and have become vulnerable to sharp declines as short sellers have targeted the troubled sector. NYSE sent an email blast to member companies over the weekend, asking them to self-certify whether or not they meet criteria outlined by the SEC ban. Institutions with financial divisions that claim to meet those guidelines are then vetted by the exchange. So far, 31 companies are included in the list, though more may be added as time goes on. Among the stocks included in the NYSE ban are General Electric ( GE), American Express ( AXP), Credit Suisse ( CS), Capital One ( COF), KBW ( KBW), M&T Bank ( MTB) and CIT Group ( CIT). The NYSE additions were first reported by the Wall Street Journal.