From the total, RM15 billion came from an agreement between Russia's Irkut Aviation Corporation, which manufactures modern jet fighters, and the Defence Ministry.
Under the agreement, Irkut will be involved in supplying spare parts and weapon systems, and producing aerospace components for the local and international markets.
In addition, 20 agreements worth RM10.355 billion were signed by the ministry and related agencies with 11 companies, including five foreign firms, during the four-day event.
The agreements comprised eight contracts, five memorandums of understanding (MoUs), three letters of agreement (LOAs) and four letters of intent (LOIs).
"The figure (RM25 billion) is the highest recorded in the organising of the series," Defence Minister Datuk Seri Dr Ahmad Zahid Hamidi said at a press conference at the Putra World Trade Centre here today.
Zahid said that Irkut had also proposed to set up a component and spare part facility at Taman Teknologi Pertahanan dan Keselamatan Malaysia which would be built soon.
"Through this collaboration, Malaysia will not only be getting benefit from the huge investment but also from the sharing of expertise and transfer of technology," he said.
Zahid said he was pleased that the participation of local companies in the biennial event had increased by 300 per cent, which would help in the growth of the defence industry.
"This year 250 local companies took part compared to only 61 companies two years ago," he said.
Zahid attributed the drop in the participation of foreign companies to several factors, including the global economic environment and difficulties in getting flights.
This year, only 500 foreign companies took part compared to 657 firms at DSA 2008.
"To ensure that this problem does not occur at DSA 2012, I will be having face-to-face communication and visits to Europe and Asia to promote the event," he said.
"The organisers should also plan their promotion and marketing strategy earlier to attract foreign participation," he added.
Overall, DSA 2010 which started on April 19 had attracted the participation of 22 countries, with most of them from Europe as well as Australia.
DSA Exhibition and Conference Sdn Bhd's director Datuk Azzat Kamaludin said the four-day event had attracted about 26,000 visitors from 60 countries.
Despite the challenges faced by several overseas participants, especially those from Europe, who eventually managed to fly in despite the flight woes caused by the ash volcanic, Azzat said the event had succeeded in providing the platform for successful networking, business collaborations and strategic alliances.
"By all accounts and based on feedback received, it was a very successful and fruitful event for exhibitors and trade visitors alike," he said in a statement on Thursday.