FRANKFURT (Reuters) - Private equity fund Warburg Pincus agreed to buy a third of United Internet's webhosting business 1&amp;1 Internet in a deal valuing the business at 2.55 billion euros ($2.82 billion), the German internet provider said on Tuesday.<div><a href="http://feeds.reuters.com/~ff/reuters/technologyNews?a=tIxturPO3Iw:2yQxHnPkaXI:yIl2AUoC8zA"><img src="http://feeds.feedburner.com/~ff/reuters/technologyNews?d=yIl2AUoC8zA" border="0" /></a> <a href="http://feeds.reuters.com/~ff/reuters/technologyNews?a=tIxturPO3Iw:2yQxHnPkaXI:V_sGLiPBpWU"><img src="http://feeds.feedburner.com/~ff/reuters/technologyNews?i=tIxturPO3Iw:2yQxHnPkaXI:V_sGLiPBpWU" border="0" /></a> <a href="http://feeds.reuters.com/~ff/reuters/technologyNews?a=tIxturPO3Iw:2yQxHnPkaXI:-BTjWOF_DHI"><img src="http://feeds.feedburner.com/~ff/reuters/technologyNews?i=tIxturPO3Iw:2yQxHnPkaXI:-BTjWOF_DHI" border="0" /></a></div><img src="http://feeds.feedburner.com/~r/reuters/technologyNews/~4/tIxturPO3Iw" height="1" width="1" alt="" />