BELGRADE, Nov 23 (Reuters) - Serbia has acquired 11 Russian-made Mi35 helicopter gunships from Cyprus as it seeks to bolster its air force and maintain regional military supremacy, country's President Aleksandar Vucic said on Thursday.

The Cypriot government and Serbia agreed in 2021 the purchase of ageing Mi35s that require an overhaul, for an unspecified price part of which Belgrade paid by exporting Serbian-made weapons.

"We have paid more than half to our Cypriot brothers with our weapons ... mainly ... artillery," Vucic told reporters at a presentation at the Batajnica military air base near Belgrade.

He also announced a sale of 48 Serbian-made self propelled howitzers worth a total of 311 million euros ($339 million) to an unspecified country. "This procedure must still go through their parliament," Vucic said. Serbia, a candidate to join the European Union that has one of the largest armies in the Western Balkans, still relies on ex-Soviet military technology, but in recent years it started purchases of Western and Chinese weapon systems and aircraft.

In June, Vucic said Belgrade was negotiating the purchase of Rafale fighter jets from France's Dassault. Serbia has already bought Airbus helicopters and transport planes.

Serbia is militarily neutral, but it joined the NATO Partnership for Peace, a programme for countries which do not aspire to join the alliance.

Belgrade curtailed military co-operation with Moscow after Russia invaded Ukraine and has condemned the invasion. But unlike the EU and other Western countries, it has not imposed sanctions on Moscow.

Serbia's military budget amounts to $1.43 billion or 2% of gross domestic product (GDP).

($1 = 0.9168 euros) (Reporting by Aleksandar Vasovic; Editing by Emelia Sithole-Matarise)