BELGRADE: Serbia raised 1.9 billion dinars ($21.8 million), or less than one fifth of the 10 billion dinars offered, at an auction of three-month debt on Tuesday, as the government prepared to revise its 2013 budget by increasing the deficit.

Domestic sales of Serbian treasury bills, both in dinars and euros, have underperformed since late May due to greater volatility in global markets and investors' concerns over an International Monetary Fund warning that Serbia's 2013 budget deficit could exceed 8 percent of gross domestic product (GDP).

The yield on the 10 percent coupon maturity rose slightly to 10.5 percent, up from 10.49 percent at a similar auction in April when an entire tranche was sold, the Finance Ministry said in a statement.

Investor demand on Tuesday stood at 2.4 billion dinars, or 24 percent of maturity on offer, it said. The ministry also said it plans to auction another 10 billion dinars in two-year treasury bills on July 2.

The government is expected to adopt a revised 2013 budget later in the day that widens the 2013 shortfall to 4.7 percent of GDP and to send it to parliament for approval.

The plan sets the 2013 budget gap at 177 billion dinars, up from a previous 122 billion dinars or 3.6 percent of GDP.

It also envisions savings of about 37 billion dinars through administrative cuts and sales of unprofitable state-run firms.