(Reuters) - Exxon Mobil XOM.N is accelerating its biggest asset sales in decades with plans to divest up to $25 billion of oil and gas fields in Europe, Asia and Africa as it sharpens its focus on a handful of mega projects at home and abroad.

FILE PHOTO: Logos of ExxonMobil are seen in its booth at Gastech, the world's biggest expo for the gas industry, in Chiba, Japan April 4, 2017. REUTERS/Toru Hanai/File Photo

The disposal program includes the sale of Exxon assets in:

- The British North Sea: The process is expected to launch in the coming weeks by investment bank Jefferies. The portfolio could fetch up to $2 billion, sources have told Reuters. Jefferies did not reply to a request for comment.

- Germany: A large onshore gas portfolio which includes over 50 fields that produced 254 million cubic feet per day of gas in 2018, according to Exxon’s annual report. The assets, which started producing in the early 1900s, are believed to be worth around $500 million, according to the banking sources.

- Romania - a 50% stake in the Neptune Deep offshore prospect in the Black Sea, worth around $250 million.

- Nigeria - Exxon is currently in talks to sell stakes in a number of its onshore and shallow water fields.

- Chad - Exxon has hired Standard Chartered to sell its 40% stake in an onshore field which gave the company around 13,000 barrels per day (bpd) of production in 2018. Standard Chartered did not reply to a request for comment

- Equatorial Guinea - Exxon is seeking to exit the West Africa country where it holds a 71% stake in Block B with net production of 27,000 bpd in 2018. It also holds 80% interests in two other blocks.

- Malaysia - Exxon has appointed Bank of America Merrill Lynch to sell its assets in the southeast Asian country that is expected to fetch up to $3 billion. The assets include 50% stakes in two production sharing contracts in 14 fields, according to a prospectus seen by Reuters. Exxon’s production in Malaysia reached 25,000 bpd of oil and 238 million cubic feet per day of gas in 2018. Bank of America Merrill Lynch declined to comment.

- Indonesia - a 45% interest in two blocks.

- Australia - Exxon said in September it was looking to sell its 50% stake in the Gippsland Basin oil and gas development in Australia’s Bass Strait as part of a broader review of its global portfolio of assets. The sale could fetch up to $3 billion, analysts and bankers said.

- Azerbaijan - Exxon is selling its 6.8% interest in the Azeri-Chirag-Gunashli (ACG) field in the Caspian Sea. The asset could fetch up to $1 billion, according to banking sources.

- Gulf of Mexico - Exxon is selling a number of stakes in fields.