UPDATE 1-HSBC sells Thai units to Bank of Ayudhya

* Bank of Ayudhya buying HSBC Thai units for around $112 mln

* Thai deal comes a day after HSBC struck Latin American asset sale

* HSBC in process of selling off non-core overseas businesses

LONDON/BANGKOK, Jan 25 (Reuters) - HSBC agreed to sell its Thai retail banking and wealth management units to Bank of Ayudhya as Europe's biggest bank continues to divest overseas operations which are no longer seen as core parts of its business.

The Thai deal comes a day after HSBC sold its banking operations in Costa Rica, El Salvador and Honduras to Colombia's Banco Davivienda for $801 million.

Bank of Ayudhya, Thailand's fifth-largest lender, said on Wednesday it would buy the HSBC Thai businesses for 3.56 billion baht ($112 million). HSBC said the gross assets being sold had a value of around 17.5 billion Thai baht, or roughly $550 million.

The Thai transaction means HSBC has sealed nearly 20 similar disposals over the past year, with the combined deals releasing more than $48 billion of risk-weighted assets.

HSBC Chief Executive Stuart Gulliver is in the process of reshaping the British bank to cut annual costs by $3.5 billion, boost its overall profits and focus more on key growth markets in Asia such as China and India.

The restructuring has seen HSBC sell its credit card business and some branches in the United States, and cut back from Russia, Poland, Chile and other countries.