The Wickes Corp. yesterday brushed off an offer of financial aid from Allegheny Beverage Corp. of Baltimore, but Allegheny officials say they are still interested in arranging a $600 million loan to keep Wickes afloat.

In a letter delivered yesterday to Allegheny, Wickes executives dismissed the Baltimore soft drink bottling company's offer as "a nonproposal" and said they weren't going to waste their time talking about it.

"It would hardly be in the best interest of our shareholders, employes, suppliers and lenders for the new management to spend its time with a financing scheme that, among other things, doesn't present terms or any indication of the ability of Allegheny to raise anywhere near the funds it is suggesting," Wickes said.

Allegheny last Friday offered to bail out the ailing San Diego-based Wickes by arranging a $600 million line of credit. Allegheny said it wanted seats on Wickes' board and the right to buy stock in return for rescuing the financially endangered $4 billion conglomerate.

Allegheny is one-tenth the size of Wickes and its offer of help was immediately likened to a mouse trying to rescue a drowning elephant.

But despite skepticism from Wall Street and outright rejection by Wickes, Allegheny is still trying. "We're persisting in seeking to meet with them to fully go over our proposal," said Harry Conn, Allegheny's chief financial officer.

The Allegheny executive said the offer to Wickes had been made point by point "in very specific form" and the ability to deliver the funds had been confirmed by Riggs National Bank, Allegheny's lead lender.

Last Friday, Wickes had a weekend massacre in which most of the top management was ousted and a new chief executive brought in. The new Wickes boss, Sanford Sigoloff, a turn-around specialist credited with saving the Daylin Corp. when he was its president, has not met with Allegheny executives.

Besides its local Pepsi-Cola franchise, Allegheny owns The Macke Company, one of Washington's biggest vending machine operators, and is parent of the D&F furniture stores.