The Commonwealth Bank of Australia Ltd (CBA) is now the leading business lender in the country as it edged out the National Australia Bank Ltd (NAB) thanks to its remarkable satisfaction levels in the market.

The Australian Prudential Regulation Authority (APRA) said on Tuesday that CBA led the pack of both financial and non-financial business lenders with 19.6 percent share in July while NAB secured the second spot with its not too remote market share of 19.1 percent.

The rest of the country's big four completed the succeeding two spots with the ANZ Banking Group getting the 17 percent share of business loan books while Westpac settled for fourth spot with its 16.2 percent share.

CBA and NAB have been locked in a battle for the tops spot as the former gained ahead in June with 19.4 percent of market share while the latter regained the lead in July by chalking up 19.3 percent of market share.

APRA said that the big four banks and three regional lenders make up for a total of 78 percent share of the country's business loan market and the rivalry among the four is expected to further heat up as they scramble to win the trust of investors over questions of future earnings.

NAB had forecasted in May that further growth earnings should be expected this year and in 2011 but a revision was announced this month by chief executive Cameron Clyne, in which he admitted that substantial movements would not come until next year.

On the other hand, in a July national survey of 7126 executives by DBM Consultants, CBA and Westpac closely fought for the lead in customer satisfaction ratings though CBA surpassed all its competitors by securing a commanding lead on satisfaction ratings given by giant corporations, which is defined by DBM as companies with more than $50 million of yearly turnovers.

Also, NAB's sterling performance in the ratings were attributed to the bank's favourable perception coming from the country's micro businesses and small and to medium enterprises (SMEs), with the DBM noting that "over the last several months its micro and small business customers have shown improving overall satisfaction with NAB."

DBM said that micro businesses have annual turnovers of less than $1 million but account for up to 90 percent of all Australian businesses while SMEs deliver yearly turnovers of between $1 and $5 million.