Nationsbank Corp. announced Monday it will provide a $300 million secured line of credit to help finance the 1996 Summer Olympics, whose officials projected a 37 percent increase in the cost of hosting the Games.

Atlanta Olympic officials told board members that expenditures would climb to almost $1.4 billion, compared to an original estimate of about $1 billion. Estimated revenues were $1.5 billion-up from an earlier projection of $1.2 billion.

"The increases were anticipated, the increases are manageable, the revenues are conservatively stated," said Billy Payne, president of the Atlanta Committee for the Olympic Games.

He said the committee now expects a surplus of $132 million, down from $157 million.

Payne said during a news conference that officals would keep their promise not to seek public funding to host the Games--and he said the loan from Nationsbank will help do it.

Nationsbank, the fourth largest bank holding company in the United States, will provide the money for ACOG's short-term financial needs, such as the cost of construction, Payne said.

The bank has $110 billion in assets.

"The line of credit gives ACOG the financial stability to support the Olympic Games without the need to turn to governmental assistance," said Kenneth D. Lewis, president of Nationsbank general bank in Atlanta.

'Honored'

"Nationsbank is honored to be selected to provide credit services needed to make the Games a success, and to be given the opportunity to express our complete faith in ACOG leadership," he said.

Payne attributed the new figures to inflation, which raised the cost of construction and operation.

ACOG officials also defended the recent hirings of relatives of committee members and government officials, but outlined a hiring policy designed to make clear which applicants have such ties.

Charges of Nepotism

"Never once did anyone demand, request or even mention employment of their relatives," Payne said.

The committee was criticized after hiring the daughter of an Olympic Games board member, the wife of City Council President Marvin Arrington, and the sister of Mayor Maynard Jackson.