NEW YORK ( TheStreet) -TheStreet Ratings' stock model upgraded GAMCO Investors ( GBL) to 'Buy' from 'Hold'. Net income at this $1.2 billion market cap, investment manager rose by 37.2% to $20.1 million in the third quarter compared to the same quarter last year. TheStreet Ratings released rating changes on 21 U.S. common stocks for November 11, 2010. In total, seven stocks were downgraded and 14 stocks have been upgraded by our stock model. In the third quarter, gross revenue at GAMCO Investors grew by 23.5% to $64.5 million over the prior third quarter. Learn more about GAMCO Investors: Company Profile, Income Statement, Balance Sheet, Stock Ratios, Analyst Ratings. $3.9 billion market cap, biomedical supply company, Beckman Coulter ( BEC) was upgraded to 'Buy' from 'Hold'. In third quarter results for Beckman Coulter gross revenue increased by 8.6% to $893.8 million while the company's bottom line gained 4367% to $67 million over the year earlier quarter. Learn more about Beckman Coulter: Company Profile, Income Statement, Balance Sheet, Stock Ratios, Analyst Ratings. -- Reported by Kevin Baker in Jupiter, Fla. For additional Investment Research check out our Ratings Research Center.