NEW YORK ( TheStreet) -- The one bright spot in banks' earnings might be beginning to lose its sheen. According to the Federal Reserve's H8 data, loan growth has begun to slow down in the first quarter of 2012. Total loans were up 4% from the fourth quarter of 2011 on an annualized basis through the week of Feb. 22, down from the 6.8% growth registered in the prior quarter. Total loan growth continues to be driven by commercial and industrial (C&I) lending, which is up 12.5% annualized quarter â¿"to- date. The first quarter tends to be seasonally weak. Still analysts said that loan growth appears to have moderated more than expected. Analysts noted that banks including U.S. Bancorp ( USB), SunTrust ( STI) and Zions Bancorp ( ZION) had been expecting a slowdown in loan growth. "We think there is some risk heading into 1Q12 earnings season for generalist investors to be negatively surprised by the overall lack of loan growth generated in 1Q12. The bar set by 4Q11 seems to be simply too high for the banks to achieve in the near term,â¿ Stifel Nicolaus analyst Chris Mutascio observed in a report. BMO Capital Markets lowered 2012 earnings estimates for Fifth Third Bancorp ( FITB) to $1.42 from $1.43, M&T Bank ( MTB) to $6.63 from $6.67 and PNC Financial Services ( PNC) to $6.35 from $6.40 on expectations of a slowdown in loan growth. Pressure continues to mount on regulators to re-write the Volcker rule. On Monday, SEC Commissioner Daniel Gallagher said regulators should "go back to the drawing board" and revise the proposed ban on proprietary trading. "Even a quick review of the many substantial comment letters the commission received reveals widespread fears regarding the effect of the proposed rules on the proper functioning of global markets and the competitiveness of the U.S. financial industry might -- fears that I share," Gallagher said in a speech at an Institute of International Bankers Institute conference in Washington, according to a Bloomberg report. Regulators have received over 15,000 comment letters on the Volcker rule from everyone ranging from banks to hedge funds to sovereign governments.