Prime Minister Lee Hsien Loong has written a valedictory letter to convey his best wishes to Mr Jose Manuel Barroso who stepped down as chief of the European Commission last month after nearly 10 years in office.

In his letter, Mr Lee said relations between the European Union and Singapore strengthened during Mr Barroso's presidency and culminated in the conclusion of the EU-Singapore Free Trade Agreement and EU-Singapore Partnership and Cooperation Agreement.

"When ratified, they will benefit our businesses and serve as building blocks for future regional agreements and further anchor relations between our two regions," Mr Lee said in a letter released by the Ministry of Foreign Affairs on Tuesday.

He also said the European Union had grown into a significant global player under Mr Barroso who oversaw the expansion of the European Union, the consolidation and structural reforms of European institutions, and the evolution of the Union towards greater integration.

"My best wishes for your continued good health, and every success in your endeavours," Mr Lee wrote.

Mr Barroso stepped down on Oct 31, 2014 as president of European Commission.

He was succeeded by Mr Jean-Claude Juncker.