UPDATE 2-Polls close in Mongolia with mining wealth in sight

* Country hopes to avoid unrest following polls

* Smooth elections important to quick approval of mine deal

* Voters hope for way out of poverty and better education

By Jason Subler

ULAN BATOR, May 24 (Reuters) - Mongolians voted on Sunday in a presidential election they hope will bring the stability needed to allow the country to tap more of its vast mineral wealth.

Polls closed at 10 p.m. (1400 GMT), but a result in the tight race between incumbent Nambariin Enkhbayar of the ruling Mongolian People's Revolutionary Party (MPRP) and opposition Democratic Party (DP) candidate Tsakhiagiin Elbegdorj is unlikely until early on Monday at the soonest.

The young democracy is hoping to avoid a repeat of the rioting that followed last year's disputed parliamentary elections, which killed five and paralysed policymaking for weeks.

Any such outcome could further postpone approval of a draft investment agreement on developing the pivotal Oyu Tolgoi copper and gold project, hampering the government's efforts to use its deposits of copper, gold, uranium, lead, zinc, and coal to help pull its nearly 3 million people out of poverty.