All remaining fuel use restrictions imposed by Gov. Mills E. Godwin on Virginia retailers three weeks ago will be allowed to expire Saturday at midnight, Godwin announced today.

The controversial orders originally prohibited any retail business or professionals in the state from being open to the public for more than 40 hours in a week. After a week of growing objections to the order, all restrictions on retail establishments heated by electricity were lifted and those using petroleum products were allowed to remain open beyond 40 hours if their heat was lowered to the minimum required to protect property.

After Saturday, the only fuel rationing in effect in Virginia will be restrictions placed on sale of natural gas to business customers in some areas. These restrictions are authorized by the State Corporation Commission, which regulates the gas industry.

Godwin's unprecedented rationing orders, first announced Jan. 29, were more severe than those imposed by other states during the weather-induced fuel shortage. They were issued in the absence of documentation that supplies of electrical energy or fuel oil had reached critical levels in Virginia.

The governor's office never offered estimates of how much fuel oil could be saved through the business-hour limits or whether any of the savings would actually result in fuel transfers to residential customers who otherwise would exhaust their supplies.

The strongest objections to the orders came from Northern Virginia where retailers share common supplies of both fuel oil and natural gas with businesses in Washington and its Maryland suburbs. No similar restrictions were placed on Washington and Maryland businesses.

The Virginia Employment Commission estimated that about 1,500 retail workers were laid off during the first week of rationing. Officials said that relaxation of the hour limits after one week prevented what they feared would become a sharp rise in retail sales unemployment.

As he announced the end of his rationing order today, Godwin praised conservation efforts by Virginians but warned that fuel supplies are still tight. " . . . Let me emphasize that this does not mean business as usual or home life back to normal," he said.

The corporation commission also announced today that it will investigate profits earned by investor-owned gas and electric utilities during abnormally cold weather.

The commission ordered utilities to file earnings statements for the months of January and February by March 31. It directed its legal and accounting staff to prepare a report on utilities' winter earnings by April 15.

Two energy-related bills were introduced in the General Assembly today at the request of Godwin. One measure calls on the State Housing Office to arrange loans for home insulation with funds that presumably will be available from the federal government and the other directs the SCC to study the feasibility of having the state's utilities loan customers the funds for home and business insulation and energy-saving devices.

The utility customers would then repay the utility thgough their regular utility bills for the cost of the insulation under. The plan is similar to a measure approved recently in Michigan.

A spokesman for former Lt. Gov. Henry E. Howell of Norfolk, a candidate for the Democratic nomination for governor, later said the measures are similar to ones Howell had proposed earlier this month and praised Godwin for the action.