The firm said pre-tax profits rose 9.7% to £203m and revenue was up 3.2% to £3.5bn after the firm secured new contracts worth £1.4bn.
Some observers had pencilled in a cut in the dividend or a rights issue in order to tackle G4S's debts, but the company instead delivered a dividend of 3.59p per share and said its debt-to-earnings ratio had improved.
G4S's total net debt pile was unchanged from December's £1.7bn.
Chief executive Ashley Almanza has been looking to shore up the company's balance sheet by winding down onerous contracts and disposing of loss-making businesses to drive down debt.
To this end, the firm sold seven businesses in the first half, raising £32m. Since 2013, G4S has offloaded 25 businesses, raising a total of £288m.
Almanza said: "Our plans are delivering tangible results. We have much to do to realise the full potential of our strategy which is underpinned by our growth, innovation, productivity and portfolio programmes.
"Executing these programmes and reducing net debt remain our key priorities."
The company also warned that it could be hit by Britain's decision to quit the European Union, saying the country's workforce and economic growth may shrink as a result of Brexit.
G4S said the "availability of skilled labour, regulation and taxation" could be affected as part of negotiations with the EU.
"Depending on the nature of the terms of the UK's exit from the EU around the free movement of capital and labour, this could result in a shortage of skills or workforce availability in the UK market.
"It is also possible that the continuing period of uncertainty lowers economic growth in both the UK and Europe which could affect both our customers and our competitors," G4S said.
However, the company added that it is "relatively well positioned, with around 80% of revenues outside the UK and minimal cross-border trading".
A G4S spokesman said: "We typically trade within national markets and have very little cross-border trade, so we anticipate that Brexit will have little impact on our ability to trade and grow. We don't operate in any of the four biggest eurozone markets of Germany, France, Italy or Spain."
"Although we haven't collected the data formally before, rough estimates would suggest that about 1% of our UK labour force are EU nationals.
"We think it's too early to say what impact a reduction in free movement would have or indeed if it will actually happen, but on the basis of the estimate we would anticipate the impact on the business to be fairly small."
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