ULAANBAATAR (Reuters) - Mongolia's parliament on Friday appointed a former finance minister as the new prime minister, amid near-flat growth and spiraling debt.

The country rich in coal, copper and gold has struggled to adapt to a changing economic environment including slowing growth in neighboring China and a reduction in the burning of coal there.

The main opposition Mongolian People's Party won parliamentary elections last month by a landslide, promising to cut debt and get more benefit from its ailing mining sector.

The new prime minister, Jargaltulga Erdenebayar, 42, was finance minister for a year under his predecessor, Chimed Saikhanbileg, who left office when a shaky alliance between Saikhanbileg's Democratic Party and the Mongolia People's Party fell apart.

Dale Choi, an analyst at Mongolian Metals and Mining, said the new prime minister was young and well-educated and "a representative of the next generation of professional Mongolian leaders".

The Mongolian People's Party leader, Miyegombiin Enkhbayar, will serve as chairman of parliament and is expected to have a hand in government affairs too.

The transformation of the former Soviet bloc state since a peaceful revolution in 1990 has been a big draw for foreign investors eyeing its rich mineral resources, unleashing a boom from 2010 to 2012.

But an abrupt economic slowdown since 2012 has stirred controversy over the role of global mining firms such as Rio Tinto, which in May finally approved a $5.3-billion extension plan for the Oyu Tolgoi copper mine.

(Reporting by Terrence Edwards; Editing by Ben Blanchard, Robert Birsel)