The Group of 7 leading industrial nations today might endorse a series of International Monetary Fund reforms demanded by the U.S. Congress, U.S. officials said. The G-7 nations, who are the IMF's major shareholders, might also back a Clinton administration proposal to create a new IMF lending system for countries facing economic problems, said officials with knowledge of the discussions. President Clinton might release the G-7 statement at the White House. The fiscal 1999 budget bill passed last week by Congress included $17.9 billion in funding to replenish IMF reserves. However, release of the funds first requires other major shareholder nations to agree to changes in the IMF's lending policies and operations. Once the other G-7 nations--Japan, Germany, France, Britain, Italy and Canada--sign off on the reforms, that would clear the way for other countries to contribute $67 billion more to the IMF, replenishing the lending agency's depleted coffers just as its gearing up to provide a large loan package to Brazil.