Argentina has asked its bank lenders for $5.45 billion in new loans and a 14-year period in which to repay its outstanding debts, banking sources said yesterday.

But bankers said the Argentine request probably is too high and the 320 lenders to Latin America's third-biggest debtor probably will end up agreeing to lend it between $3 billion and $5 billion in new funds before the end of 1985.

Argentina negotiated with the International Monetary Fund for nine months before reaching an accord late last month during the IMF's annual meeting in Washington. Banks insisted they would not discuss lending Argentina new money or renegotiating the terms on its outstanding loans until an IMF pact was reached.

Argentine officials, led by central bank president Enrique Garcia Vasquez, began negotiating with a bank committee this week and will resume talks next week. Argentina has foreign debts of about $45 billion -- about $20 billion of which is bank debt that already has come due or will come due in the next few months.

A banker said the $5.45 billion figure represents the difference between interest payments the country needs to make and the net foreign reserves it has available according to its best estimates. But a bank official said there are other sources of funds Argentina can tap, such as official lending and government-guaranteed trade credits, to reduce its bank-borrowing needs.

Argentina took longer than other debtor nations to reach an IMF pact and begin talks with bank lenders.

As a result, the nation is far behind in interest payments due bank lenders and many U.S. banks have put a sizeable portion of their Argentina loans on their problem lists.

The Argentine request is patterned on the long-term agreements reached between Mexico and Venezuela and their bank negotiating committee.