As we have an inquiry to build a lottery system in my country so I
need to know the names and website addresses of the best companies
which provides major lottery solution world wide.

http://plus.maths.org/issue30/features/haigh/

This isn't quite what you're looking for, it is a beginners guide to
running a lottery.
I'm not certain the type of company you are looking for exists. 
Countries who run loteries tend to run them independantly from my
understanding (rather than paying 5%-10% of their profits to an
outside organization).

I will suggest however that you heavily consider the lottery idea as
it almost always tends to end up as a tax on the poor.  Poor people
are much more inclined to play the lottery than rich people are, and
of course on average they lose much more money than the win.

"Firstly, that the lottery is a tax on the poor, since the poorest 10%
of households spend around 3 times more of their weekly income on
lottery tickets than the top 10% of households"

http://www.bbc.co.uk/politics97/issues/lottery.shtml

One of the partners in the Camelot consortium is/was GTech. From the
link that jack-of-few-trades posted,
"Shareholders include Cadbury Schweppes, Racal, De La Rue, ICL, GTech"

 "GTECH has operations in 36 countries on six continents and is the
on-line lottery technology provider to 28 of 38 government-authorized
lotteries in the United States. All told, two thirds of the world's
automated government- authorized lotteries have selected GTECH to be
their on-line lottery technology and service provider."
http://www.gamblingmagazine.com/articles/19/19-64.htm

Contact information
http://www.lotteryinsider.com/vendors/gtech3.htm

There are other links to other vendors and consultants at
http://www.lotteryinsider.com/vendors/
http://www.lotteryinsider.com/classifieds/index.htm

Owain