U.S. municipal bond sales to sink to $59.6 million

June 29 (Reuters) - U.S. municipal bond sales next week are expected to drop to the lowest weekly total in more than 20 years with issuance estimated at only $59.6 million, according to Thomson Reuters estimates on Friday.

The coming week will also mark a huge plunge in supply from this week's estimated $9.5 billion in bond sales.

The sparse calendar comes as Wednesday's Fourth of July holiday will shorten the coming trading week to four days with participation in the $3.7 trillion market expected to be limited.

In June, states, cities, schools and other issuers sold $40.6 billion of debt, according to Thomson Reuters data.

At this time there are no negotiated issues scheduled to price next week. This week, negotiated issues totaled an estimated $7.6 billion in 76 deals compared.