SYDNEY, April 15 (Reuters) - Commonwealth Bank of Australia (CBA), the country's largest lender, said growth in its home loan book this year should boost the company's mortgage profit in the order of 3%, Chief Executive Officer Matt Comyn said on Thursday.

Speaking at a twice-yearly parliamentary session with the country's top banks, Comyn said CBA expects to grow its $378 billion home loan book by about 5% this year with demand for mortgages buoyed by near-zero low interest rates.

A strong economic recovery from the COVID-19 pandemic, fuelled by easy monetary policy, paired with a "miraculous" turnaround in the labour market, will likely push record house prices even higher, Comyn added.

Job creation in March outstripped expectations with unemployment falling to 5.6% from a recent peak of 7.5% in July, government data showed on Thursday.

"We're anticipating credit growth of about 5% over the course of the year," Comyn said. "Our forecast for housing (price growth)... I suspect it's probably closer to 10% at this particular point in time."

Asked whether a 5% increase in CBA's home loan book would lead to an equivalent rise in mortgage profit, Comyn said factors such as bad debt and price-based competition meant profit would be slightly lower. Pressed on whether that meant a 3% increase, Comyn said, "It could be in that order."

"We've also seen the highest level of refinancing, in the market, that I think we've ever seen," he said, adding that business lending growth, however, would be much lower.

While official interest rates dropped to a record low of 0.1% last year, major banks protected profit margins by not passing on the cuts to the majority of customers with variable mortgages, and instead lowered rates on fixed-rate loans.

That dynamic continues to lead many customers to refinance mortgages to secure cheaper debt.

CBA - the biggest of Australia's Big Four banks by assets followed by Westpac Banking Corp, National Australia Bank and Australia and New Zealand Banking Group - reported A$3.89 billion ($3 billion) in cash profit for the six months to Dec. 31, a 10% fall from the previous year.

Together, the four command the majority of the country's A$1.8 trillion housing loan market.

Westpac's CEO Peter King, who appeared in the afternoon, matched CBA's expectations for housing and credit growth, but declined to given any forecasts on the impact of that growth on profits.

($1 = 1.2965 Australian dollars) (Reporting by Paulina Duran in Sydney; Editing by Christopher Cushing and Ana Nicolaci da Costa)