Massar Solutions announces first Abu Dhabi share float since 2011

* To sell 240 mln shares at 2.4 dhs each * IPO to run Jan 11-25 * Existing shareholders to sell combined 40 pct of firm * Follows recovery of markets, economy from crisis * But oil price slide has hit UAE markets in recent weeks (Adds detail, context) DUBAI, Jan 5 (Reuters) - Massar Solutions, a United Arab Emirates vehicle rental and fleet management firm, said on Monday it planned to list 40 percent of its shares on Abu Dhabi's bourse, in what would be the first flotation on the emirate's stoc