Two of Australia's biggest banks, Westpac and St George, say they have agreed to key terms of a proposed merger, opening a two-week period for them to examine each other's books and negotiate finer details of the deal.

However the board of St George Bank has already said it will recommend to shareholders that they accept 1.31 Westpac shares for each St George share they hold in the $A19 billion takeover bid .

Westpac's chief executive officer, Gail Kelly, told banking analysts that both organisations share similar cultures.

"This is exciting and it's very much an agenda about growth," she said.

"But we believe it offers value for shareholders, for customers and for our people."

Watchdog to review Australian bank merger
The Australian Competition and Consumer Commission says it has not yet received any submissions from the parties, but it will review the proposal.

The ACCC's former chairman, Allan Fels, says there are big issues of competition.

"Both for small business and for consumers, big business can look after itself," he said.

The Finance Sector Union's national policy director, Rod Masson, says he will be taking the union's competition concerns to the treasurer once the federal budget is out of the way.

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