* To pay 12.50 euros per Porthus share
BANGALORE, Dec 14 (Reuters) - Canada's Descartes Systems Group Inc (DSG.TO) (DSGX.O), which provides logistics management software and services, said it intends to buy Belgium's Porthus (ALPTH.BR) for about 29.7 million euros ($43.5 million) to 30.3 million euros to boost its presence in Europe.

* Offer represents 20 pct premium to prior close

* Porthus' management supports offer

* Descartes shares up 6 pct, Porthus jumps 18 pct (Adds details, analysts' comments, updates stock movement)

Descartes said it would offer 12.50 euros per Porthus share, a premium of 20 percent to the stock's Friday close, and pay 12.33 euros for warrants issued after April 2000 and 20.76 euros for those issued after November 2001.

The acquisition looks like a good fit for the company. It will put them in the leadership position in the industry, analyst Pradeep Sangha of PI Financial Corp said.

Sangha, who has a buy rating on Descartes stock, said the deal was likely to increase the company's revenue by about 50 percent in 2010.

Porthus' board of directors and executive management have expressed support for the offer, which is expected to commence by the end of January and close by March-end, Descartes said.

With plenty of cash in hand, the company might continue to expand in the near future, analyst Sameet Kanade of M Partners Inc told Reuters.

You can expect them to do if not similar, at least a tuck-in acquisition in China, because that is one major block where they have don't have a significant presence, Kanade, who considers Descartes as one of his top picks, said.

Earlier this month, Descartes signed an agreement to partner with New Trend International Logistics Technology Ltd, a Chinese material handling technology provider, to extend and accelerate logistics technology infrastructure throughout China.

As of Dec. 11, Porthus had 2.3 million shares outstanding and 23,759 warrants convertible into 71,277 additional shares, Descartes said. Shares of the Waterloo, Ontario-based Descartes rose 6 percent, or 35 Canadian cents, at C$5.99 in afternoon trade Monday on the Toronto Stock Exchange.

Porthus shares jumped 18 percent to 12.25 euros. ($1=.6828 Euro) (Reporting by Amit Kumar in Bangalore; Editing by Deepak Kannan and Anil D'Silva)