LONDON - The U.S. and China on downgrade warnings, Turkey hoping for its first upgrade in a decade and Israel facing its first cut - plus more than 50 elections to navigate - means 2024 could bring pivotal moves in some sovereign credit ratings.

Next year might be starting with highest share of "stable" sovereign ratings for years, but with record debts now meeting higher borrowing costs, spluttering growth and multiple wars, there are big names are in play.

Moody's has negative outlooks on both the United States and China, the world's two biggest economies. A downgrade would cost the U.S. its only remaining triple-A rating.

Marie Diron at Moody's said it wants to see if Washington can address a threatened "very steep deterioration in debt affordability" and whether China can stop its property and local government debt woes worsening.

Fitch, which downgraded the U.S. in August, and S&P Global are also keeping a close eye as November's presidential election approaches.

"Many of the factors we pointed to with the (U.S) downgrade remain in effect," Fitch's Ed Parker said, explaining that higher interest rates, defence spending and an aging population would all keep U.S. debt levels rising.

Fitch sees Chinese growth dipping to 4.5%-5% but has also modelled a "hypothetical stress scenario" where the property sector and other problems cause it crater to just 1.5% and only recover to 2% in 2025.

"A downgrade would be likely in such a scenario," Parker said, although "we wouldn't expect more than a one-notch move" given China's broader strengths.

Turkey meanwhile could see its first upgrade in over a decade, if President Tayyip Erdogan's new finance minister and central bank head keep policy repair efforts going, and Oman could be elevated to investment-grade.

Moody's Diron said Turkey's local elections in March will test authorities' resolve in sticking with 40%-plus interest rates but that if they maintain course and foreign investors start returning, "that would point to positive momentum".

OMAN, PANAMA AND ISRAEL

Securing investment-grade status would see Oman's bonds added to the global fixed income indexes giant pension funds use like a shopping list and drive what analysts estimate could be $3 billion of inflows that would cut its borrowing costs.

Oman has been upgraded two years running, S&P's Frank Gill said, adding: "At the end of the day they are still very sensitive to the price of oil but tax revenue as a percentage of GDP is now over 31%, which is notable for a resource-driven economy."

In contrast, Panama looks most in danger of dropping to "junk" as it goes through the painful process of shutting one of the world's biggest copper mines, which provides around 5% of its GDP.

Morgan Stanley has tipped a downgrade to happen around May when elections are due, and at BBB- with a negative outlook Fitch looks closest to doing the deed.

"It is one where we have been flagging some negative developments," Fitch's Parker said. "It will certainly be an interesting credit for 2024."

Italy's huge debts will keep it under scrutiny, while Spain, Germany and election-bound Britain still spend at least 4 percentage points of GDP more than pre-COVID.

S&P also expects to make a decision on whether to lower France from AA. "We are likely to resolve it (France's rating decision) by the end 2024," Gill said. With debt-to-GDP expected stay at almost 110% in the coming years "we are watching to see if they deliver additional fiscal reforms".

Israel's war with Hamas could meanwhile prompt its first ever ratings cut.

It is on negative outlook with S&P while both Fitch and Moody's have applied their most imminent downgrade warnings - "rating watch negative" and "rating under review" - meaning both could potentially deliver cuts in the next month or two.

With Yemen's Iran-aligned Houthi rebels now attacking Israel-bound ships in Red Sea, there is a "huge amount of uncertainty how long the war will go on for, or what comes after", Fitch's Parker said.

Israel's deficit is now likely to be 5 and 5.5 percentage points of GDP this year and next, S&P's Gill added, although its $200 billion of foreign exchange reserves more than covers all its international debt.

"It definitely could move," Gill said. "But we are talking about a transition from AA- to A+."

(Editing by Catherine Evans)