Buy-to-let landlords remain confident despite the global credit crunch, figures showed today.

Nine out of 10 landlords questioned during the final quarter of 2007 said they had no intentions of selling their properties, with people instead planning to hold on to them for an average of nearly 17 years.

Less than one in 10 people think they will sell up within five years, and only two per cent see property as a short-term investment of less than two years.

At the same time four out of 10 landlords said they planned to increase their investment in bricks and mortar this year, according to the Association of Residential Letting Agents.

Ian Potter, head of operations at ARLA, said: "This is good news for the whole of the private rented sector and for the housing market, particularly as it comes from surveys carried out well after the credit crunch had begun to bite.

"The rental sector is the linchpin for all our housing requirements and needs continual investment from private individuals as it still suffers from a lack of investment from the institutions."

Investment landlords borrowed an average of 70 per cent of a property's purchase price during the three months to the end of December, down from 74 per cent in the previous quarter, while around one in six borrowed less than half a property's value.

Although the majority of investors who bought a new property during the past quarter bought an existing house or flat that was in good condition, 7.5 per cent said they had bought a new property off-plan.

Mr Potter said: "Buying off-plan flies in the face of the continuous warnings given by ARLA and the ARLA Group of Mortgage Lenders that this kind of property investment cannot make for a realistic buyto-let investment proposition.

"The rental market is too fluid to make judgments on rental values and likely demand months or even years in advance, for property that has yet to be built.

"We cannot repeat this warning often enough."

A survey carried out by Alliance & Leicester also showed that the majority of people investing in buyto-let properties were taking a long-term view, with the average landlord saying they planned to hold on to their property for around 18 years.

Nearly two-thirds of those questioned said they planned to continue renting out their property because they were happy with the income they were getting.

Only 21 per cent of landlords said they saw their property as being a short-term investment, and they planned to cash it in within the next five years.

Around 57 per cent of people said they had invested in property to build up assets for the future, such as to fund their retirement or to pay for a child to go to university.

But 11 per cent of those questioned said they earned more than half of their monthly income from their buy-to-let properties.

The majority of landlords are renting out properties alongside doing another job, with just four per cent regarding it as their full-time profession.