* 2023 EBITDA jumps 130% to 439 million euros

* Defence accounted for more than 70% of revenue

* To more than double high-caliber ammunition production in 2024

PRAGUE, April 10 (Reuters) - Czechoslovak Group (CSG) more than doubled core earnings in 2023 and forecast continued strong demand for its heavy military equipment and large-caliber ammunition as countries ramp up defence spending amid war in Ukraine and elsewhere.

Since Russia's full-scale invasion of Ukraine in 2022, the Czech defence and industrial manufacturer has raised large-caliber ammunition production several-fold.

"We are really facing high demand," CSG Chief Financial Office Zdenek Jurak said on Wednesday.

Even if fighting in Ukraine were to stop, CSG said re-stocking by NATO members, which have helped arm Ukraine, would drive growth.

CSG's earnings before interest, tax and amortisation (EBITDA) jumped by 130% to 439 million euros ($476 million) in 2023, on revenue up 71% to 1.73 billion euros. Net profit rose 49% to 210 million euros.

The company, which employs more than 10,000 at 37 sites in Europe and the United States, said defence accounted for more than 70% of its revenue.

Owned by Czech billionaire businessman Michal Strnad, 31, CSG has been investing in ammunition production at its plants in Slovakia and Spain. It aims to more than double production of high-caliber ammunition this year, it said.

CSG also makes self-propelled howitzers, multiple rocket launcher trucks and other heavy equipment, and has upgraded Soviet-era tanks and infantry fighting vehicles for shipments to Ukraine.

The firm said its Excalibur Army unit, which makes and upgrades heavy military equipment, added 400 jobs last year, while the workforce at its artillery ammunitions division MSM Group had nearly doubled in the past 18 months.

The company is also in the process of a $1.91 billion all-cash acquisition of the Sporting Products division of U.S.-based Vista Outdoor, since renamed Kinetic Group, which includes its guns and ammunition production business.

Apart from military sales, CSG last year fully integrated Fiocchi Munizioni, a maker of small-caliber ammunition, mostly for civilian use, which it acquired in 2022.

CSG's aerospace business, which includes radar and security systems and airplane servicing, also grew.

($1 = 0.9217 euros) (Reporting by Jan Lopatka and Jason Hovet; editing by Jason Neely and Mark Potter)