Mexico sees big potential near Tsimin oil find

* Tsimin, Xux fields may hold more than 1.5 bln bls oil

* Nearby prospects look promising

* Finds prompt Pemex to step up activity in region

By Robert Campbell

MEXICO CITY, Aug 30 (Reuters) - Mexico's state oil company Pemex is increasingly optimistic about the potential of what appears to be a new cluster of light crude oil fields around its Tsimin discovery, according to company executives.

The side-by-side Tsimin and Xux discoveries are believed to hold the equivalent of 1.5 billion barrels of proved, probable and possible oil reserves said Manuel Teran, a Pemex engineer working on the discoveries, at a petroleum engineering conference this weekend.

"We are also optimistic that nearby locations could be similarly productive," Teran said.

Pemex [PEMX.UL] plans to drill additional exploratory wells at the two finds to allow it to reclassify the oil discoveries as proven, Teran said.

If Pemex succeeds in its efforts to reclassify Tsimin and Xux, the two fields would account for more than 10 percent of Mexico's total proven oil reserves.