Property developers should be cautious in launching new projects this year and non-listed firms should avoid competition in markets where large conglomerates have joined the fray, industry experts warn.

Opas Sripayak, managing director of SET-listed L.P.N. Development Plc, said the condominium market in the middle- to lower-priced segment may not match its performance of recent years, due to a large amount of supply remaining in the market.

"Condo units priced at 2 million baht or lower had good sales in the past two years," he said. "Most of the projects in this segment recorded a sales rate of over 50% or up to 100%. But the situation this year is not as good. Sales of 30% may not be unusual."

Bank rejections of mortgage loan applications are one big issue. Many buyers who booked a unit were unable to get a home loan because of problems with the credit bureau.

"In the past few years, developers focused on large-scale condo projects," Mr Opas said. "Some sites had a project value as large as 5 or 6 billion baht. But things have changed this year. Such large-scale projects are very risky as the market is not that good."

According to Therdsak Thaveeteeratham, executive vice-president of Asia Plus Securities, presales of 15 SET-listed developers in the first quarter totalled 48 billion baht, down 3.3% from the same period last year and down 9.7% from the fourth quarter of 2015.

Their combined sales backlog fell to 165 billion baht from 176 billion at the end of last year. The amount included 139 billion baht from condos, down from 176 billion. Some 26 billion baht was from low-rise units, up from 23 billion.

The figures exclude sales from joint venture projects.

Samma Kitsin, director-general of the Real Estate Information Center, said presales dropped as many developers focused on existing projects where there were ready-to-transfer units during the effective period of property tax incentives.

The period, November 2015 to April 2016, saw the number of condos and low-rise units transferred in Greater Bangkok rise by 106% and 23% respectively from a year earlier.

Roongrat Limthongthang, managing director of property developer Suetrong Group Co, said it would be difficult this year for non-listed developers to do business because of greater competition from large companies such as TCC Group, Boon Rawd Brewery, CP Group and CPN.

"The property market last year was better than in 2014 by 10%, but this year competition is getting higher after the entry of large firms with strong financial backup," he said. "These groups have somewhat larger funds than the industry's top five."