BELGRADE, Aug 10 (Reuters) - Serbia's January-June current account deficit fell to less than a third of its level in the same period last year, on slowing trade and investment, central bank figures showed on Monday.

The six-month balance of payments figures put the current account deficit at $1.28 billion, compared with a gap of $4.7 billion in the same period last year.

"It may be good news, but the bad thing is the reason behind the improvement," said Milojko Arsic, a member of the central bank's supervisory board and adviser to the Serbian prime minister. "The current account deficit has been falling because of lower imports and falling demand for both consumer durables and capital goods," Arsic told Reuters. "The adjustment is welcome in terms of long-term sustainability, but it also reflects a fall in purchasing power and a lack of foreign financing.

Heavily reliant on foreign investment and borrowing, Serbia has run big current account gaps for years and the balance of payments turned positive in May for the first time since 2001.

According to International Monetary Fund figures, the deficit is expected to drop to 13 percent of GDP in 2009 from an estimated 17.1 percent of GDP in 2008, but the IMF will revise its forecasts for Serbia later this year, to reflect a deeper than initially forecast economic contraction.

Serbia's GDP shrank by 3.5 percent in January-March. The IMF has forecast a 2.0 percent full-year contraction. SERBIA BALANCE OF PAYMENTS JAN-JUNE JAN-JUNE 08 JAN-DEC08 CURRENT ACCOUNT BALANCE (mln USD) - 1,285 - 4,748 - 8,721 - Goods - 3,153 - 5,798 -11,256 - Services - 19 - 72 - 255 - Income - 293 - 693 -1,356 - Current transfers 2,181 1,815 4,146 CAPITAL ACCOUNT BALANCE 1,345 2,261 8,879 - Capital account - 2 21 20 - FDIs 1,168 2,240 2,717 - Portfolio - 87 - 132 - 134 - Other investments 1,111 2,375 3,926 - Central bank financing - 844 438 2,350 ERRORS AND OMISSIONS - 60 - 195 158 (Reporting by Gordana Filipovic; Editing by Stephen Nisbet)