(Bloomberg News) Dodd-Frank Act implementation should be delayed by U.S. regulators until concerns over global coordination of new rules can be addressed, Senator Orrin Hatch (R-Utah) said in a letter to Treasury Secretary Timothy F. Geithner.

Hatch, the top Republican on the Senate Finance Committee, asked Geithner to provide details of international coordination in advance of this week's meetings of the Group of 20 finance ministers, the World Bank and the International Monetary Fund.

"There are significant outstanding issues surrounding global coordination," Hatch wrote in the letter to Geithner dated April 8. "These concerns demand delay of further implementation and rulemaking of Dodd-Frank Act provisions until and unless we receive assurances that international partners agree to adopt similar regulatory reforms."

U.S. regulators including the Federal Deposit Insurance Corp. and the Securities and Exchange Commission are writing hundreds of rules to implement the law enacted last year. Many must be completed by July 21--the one-year anniversary of President Barack Obama signing the rules into law.

Hatch requested information on the implementation, as well as reports on consultations with other G-20 nations. He also focused his requests on whether there is international agreement on the Volcker rule, a provision that would bar banks from engaging in proprietary trading.

Finance ministers and central bankers from around the globe are scheduled to meet Washington this week for the semiannual meetings of the International Monetary Fund and World Bank. Finance officials from the Group of 20 meet on April 15, and the International Monetary and Financial Committee, the IMF's steering committee, meets on April 16.