Ratings agency Fitch downgraded the ratings of Spain's fourth-biggest bank, Banco Sabadell, by a notch on Wednesday owing to its exposure to the collapsed real estate market and weak economy.The agency said it had trimmed the Barcelona-based bank's long-term debt rating to "A-" from "A" with a negative outlook."The vast majority of Sabadell's activities are undertaken in Spain and thus its performance is highly correlated with that of the Spanish economy, which has uncertain growth prospects and has suffered from the collapse of the property sector," Fitch said in a statement."Like many Spanish banks, this is likely to continue affecting asset quality and profitability," it added.Banco Sabadell's exposure to the real estate sector totalled 10.8 billion euros ($15.4 billion), and repossessed...