UPDATE 1-Mitsubishi Heavy delays jet delivery to 2014

* Says delivery to be in Jan-March 2014

* Shares close down 0.8 pct, in line with Nikkei

TOKYO, Sept 9 - Japan's Mitsubishi Heavy Industries Ltd said it was delaying delivery of its first passenger jet by three months to the first quarter of calendar 2014 due to design changes.

Mitsubishi Heavy, which competes with Canada's Bombardier Inc and Brazil's Embraer, previously planned to have its jet, dubbed the Mitsubishi Regional Jet, in the air in 2013.

Mitsubishi Heavy will change the material used in the wings to aluminium instead of carbon fibre for better fuel efficiency, and will widen the body of the jet and expand cargo space.

It is also considering making jets that will seat 100 passengers, in addition to the 70-person and 90-person jets now planned.

The design changes will not affect development costs for the jet, it said.

Mitsubishi Heavy, which aims to sell 1,000 of its jets over the next 20 to 30 years, said it will hold the first test flight for its jet in the second quarter of 2012, instead of 2011.

All Nippon Airways Co, Japan's second-largest airline, has said it will buy up to 25 of the jets.

Prior to the announcement, Mitsubishi Heavy's share price closed down 0.8 percent, in line with the benchmark Nikkei average.