Almost one in three new buy-to-let mortgages have initial terms lasting at least five years as intermediaries place more longer-term business.
Fixed rates remain most popular overall, responsible for 79% of cases, although there has been a small revival in the number of brokers setting up trackers.
Paragon Mortgages’ quarterly intermediary tracking survey showed 30% of buy-to-let cases were for terms of five years or more.
This covers both trackers and fixed rates and is an increase on the previous quarter's figure of 26%.
The number of two and three-year terms dropped from 71% to 66% over the same period.
Tracker products have seen their popularity steadily decline over the last three years but this trend now appears to be shifting. Tracker products accounted for 18% of cases in Q1 2015, up from 15% in Q4 2014.
Despite the modest improvement in the sale of tracker products, intermediaries recommend a fixed rate product in four out of every five sales.
Intermediaries are also feeling more positive about future levels of mortgage business, with those surveyed expecting a 6% increase in case volumes in the second quarter.
John Heron, managing director, said: “The gap between fixed rate and tracker rate sales widened significantly from the start of 2012, and it is not since 2010 that we have seen tracker and fixed rates selling in equal numbers.
“While concerns over imminent increases in interest rates may have abated, it is clear that landlords are continuing to take a cautious approach by selecting fixed rates in much larger numbers and over longer period.”