ALGIERS, Sept 10 (Reuters) - Oil and gas producer Algeria has made an $800 million early debt repayment to the London Club of commercial lenders, the official APS news agency quoted Finance Minister Mourad Medelci as saying on Sunday.

The creditors were paid following an accord signed in London at the end of last week, Medelci said, according to the agency.

"With regard to the debt contracted to the London Club estimated at $800 million, the minister announced that not only was the agreement of repayment in advance signed at the end of last week in London but that the creditors were already paid by Algeria," APS said.

The deal follows an accord with the Paris Club group of creditor countries in May under which members accepted Algeria's offer to prepay up to $8 billion of debt at par.

Repayment will take place on a voluntary basis between May 31 and November 30 after the conclusion of bilateral agreements.

Analysts say the key objective of both the London and Paris Club repayments has been to improve Algeria's image among international investors in the hope of securing a credit rating.

Medelci added the London Club repayment took the total amount of external debt settlement agreed by Algeria since 2004, including a write-off of debt owed to Russia, to about $16 billion.

He said without giving details that the OPEC member nation had recently repaid a total of $4 billion to international institutions such as the World Bank, International Monetary Fund and the African Development Bank.

Russia agreed to write off $4.74 billion of Algeria's Soviet-era debt during a visit by President Vladimir Putin to the giant Mediterranean country in March.

President Abdelaziz Bouteflika said on Monday the country's foreign debt had fallen to $9.0 billion at the end of July this year from $15.5 billion in February and would reach $5.0 billion by the end the year.

Algeria repays $800 million to London Club creditors