Subex Azure, a telecom software product firm, is making the largest-ever overseas acquisition by an Indian software player by acquiring Canada-based Syndesis Limited for $164.5 million (around Rs 740 crore or Rs 7.4 billion) in an all-cash deal.

The acquisition surpasses Subex's own record of acquiring Azure for $140 million (around Rs 620 crore or Rs 6.2 billion) in July last year. Syndesis enters the Subex fold with 400 people, taking the total headcount to 1,200.

Subex Azure plans to finance the acquisition through a $200 million (around Rs 890 crore or Rs 8.9 billion) GDR issue on a premier European exchange.

"We have received shareholders' approval for this and we expect the offering and the acquisition to be complete within March 31," said Subash Menon, chairman, Subex Azure. For the last fiscal, Subex had a topline of close to Rs 250 crore (Rs 2.5 billion).