BANGKOK, May 20 (Reuters) - Thailand's economy expanded 1.5% in the first quarter from a year earlier, official data showed on Monday, beating analysts' expectations.

On a quarterly basis, Southeast Asia's second-largest economy grew a seasonally adjusted 1.1% in the January-March quarter, data from the National Economic and Social Development Council showed.

The quarterly growth meant the economy avoided a technical recession, after it had contracted by a revised 0.4% in the final quarter of 2023.

Economists in a Reuters poll had forecast gross domestic product (GDP) to expand 0.8% in the March quarter from a year earlier and 0.6% from the previous three months.

In the fourth quarter of 2023, GDP grew an annual 1.7%. (Reporting by Orathai Sriring, Kitiphong Thaichareon, Satawasin Staporncharnchai, Chayut Setboonsarng; Editing by John Mair)