NEW YORK, May 3 (Reuters) - U.S. municipal bond sales are expected to fall next week to $5.78 billion from this week's total of $6.4 billion, according to Thomson Reuters estimates released on Friday. Negotiated sales next week are expected to total $3.78 billion in 79 issues, compared with $5.3 billion in 79 deals this week. Missouri's Higher Education Loan Authority will sell $970.8 million of student-loan, asset-backed LIBOR floating rate notes through Morgan Stanley. The notes carry a final maturity date of June 25, 2032, according to the preliminary official statement. Morgan Stanley will also price $202 million of sales tax refunding bonds for Colorado's Regional Transportation District. Competitive deals are expected to total $2 billion in 109 sales compared with $1.1 billion in 61 issues in the week ended May 3. Illinois will sell on Thursday $300 million of taxable sales tax revenue bonds to be offered with serial maturities from 2013 through 2037, according to the POS. The Build Illinois Bond deal will be the state's first revenue bond sale since about a year ago, John Sinsheimer, the state's capital markets director said earlier this week. The sale will mark the state's second trip to the $3.7 trillion municipal bond market so far this year. On April 2, Illinois sold $350 million of taxable and $450 million of tax-exempt GO bonds in competitive deals that each attracted bids from nine banks. Fitch Ratings on Thursday assigned the bonds a AA-plus rating, which is four notches higher than the state's A general obligation bond rating. The Build Illinois bonds are supported by the state's sales tax revenues, which are currently rebounding. In fiscal 2012 the sales tax generated almost $7.7 billion, according to Fitch. On Tuesday, Louisiana will sell $300 million of GO bonds in a two-part sale. The deal consists of $130.7 million of tax-exempt bonds with serial maturities from 2014 through 2033 and $169.3 million of taxable bonds with serial maturities from 2014 through 2026, according to the POS.