LONDON - Just over $17 billion of Ukraine's newly restructured government bonds are to be added to the world's most widely tracked emerging market debt indexes on Thursday, JPMorgan, the bank that runs them, has said.

The U.S. bank said the move would happen in a "intra-month rebalance" and lift the war-torn country's "weighting" in its 70-country EMBI Global Diversified index increase by 14 basis points to 1.05%.

Indexes like JPMorgan's are important because investment funds and other money managers use them as a key gauge of their own performance, meaning the bonds within them are often bought far more than alternatives that are not.

Ukraine's new weighting will put it 30th in the overall EMBI GD list between Costa Rica and Angola with 1.14% and 1.15% and Ghana and Kazakhstan which both have a 0.94% weighting.

The countries that top the index will remain Saudi Arabia, Mexico and Indonesia with 5.11%, 4.93% and 4.57% respectively.

In JPMorgan's other flagship indexes, the EMBI Global, Ukraine's weighting will increase by 8 basis points to 0.61%, while in the Euro EMBI Global Diversified index for euro-dominated debt it will drop 42 basis points to 0.35%.

The moves come after Ukraine sealed a vital debt restructuring at the end of last month.

It was the second in a decade forced by a Russian invasion and saw bondholders accept a 37% writedown, or "haircut", to the face value of their bonds.

(Reporting by Marc Jones Editing by Gareth Jones)