Real estate mogul Donald J. Trump and four major banks worked late into the evening yesterday in an attempt to hold together a multibillion-dollar refinancing agreement that appeared to be in danger of unraveling.

A breakdown of the agreement, put together last weekend, could cause Trump to miss a crucial deadline today, when $25 million in interest and other payments come due on bonds Trump issued to build his three Atlantic City casinos.

The four major lenders -- New York banking giants Chase Manhattan Corp., Citicorp, Bankers Trust of New York Corp. and Manufacturers Hanover Corp. -- have been struggling to devise a plan that would provide Trump with enough cash to avert a financial meltdown of his troubled empire of airplanes, casinos and hotels.

To give Trump more time to meet his obligations, the banks had tentatively agreed to loan him $60 million in fresh cash and suspend interest on $2 billion in bank debt in exchange for a major restructuring of his empire that would put a larger portion of his properties up as collateral.

But the plan required the approval of the 50 banks that had bought portions of the loans held by Trump's four largest bank creditors. Many of those banks believe they have more to gain by refusing to sanction the restructuring, according to industry sources.

Chase, which had backed the original plan, reportedly has balked at working out a new agreement to overcome the objections of the smaller banks. A new plan would require Chase and the other major lenders to buy out the loans held by some of the 50 other creditors, an expense banking sources say Chase is unwilling to bear. Chase officials did not return telephone calls. Trump also declined comment.

If the smaller creditors refuse to grant Trump relief, and if the four major banks refuse to buy the smaller creditors out or lend Trump more money, Trump could find himself unable to meet interest payments in coming months. That could force the banks to declare him in default. So far, Trump has met his payments.

If Trump misses today's deadline, his image may be slightly bruised, but he still has some room to maneuver; the terms of the securities give him a grace period of an additional 10 days to come up with the money. "He'd be better off paying it {today} but it's not the end of the world -- but only if he makes the payments within 10 days," said Gary Heindes, chairman of The Delaware Company Inc., a New York firm that follows distressed securities. The firm started watching Trump's $1 billion in junk bonds in January.