NEW DELHI, Jan 23 (Reuters) - Billionaire Gautam Adani's

aerospace and defence business and Brazil's Embraer ( EMBJ ) will

announce a tie-up next week to assemble commercial aircraft in

India, a source with direct knowledge of the matter ‌said,

boosting the country's civil aviation industry.

Assembling aircraft in India would mark ​a significant win for

the Indian government, which has long ‍urged planemakers to build

jets domestically, citing more ⁠than 1,500 aircraft ⁠orders from

Indian carriers. Planemakers have until now pushed back, arguing

in part ‌that the business case did ​not add up.

Adani Aerospace has signed a memorandum of understanding

with Embraer ( EMBJ ), the world's third-largest planemaker

behind ⁠Airbus and Boeing ( BA ), to set ‍up ​a final assembly line for

its regional jets in India, the source said.

Adani Aerospace and Embraer ( EMBJ ) sent invitations ‍to the media

teasing a "historic" development in commercial aviation on

Tuesday. The announcement will be made at the office of India's

civil aviation ministry, the invitation said.

Embraer ( EMBJ ) declined to comment, while Adani Aerospace and

India's civil aviation ministry did ​not ‍immediately respond to

requests for comment. The pact was earlier reported by The Times

of India newspaper.

Nearly 50 Embraer ( EMBJ ) ​aircraft of various types operate in

India, including civil aircraft flown by regional carrier Star

Air. The fleet is much smaller than the Airbus and Boeing ( BA )

aircraft that dominate Indian airlines' order books.

Embraer ( EMBJ ), which opened an office in New Delhi last year, has

forecast ​that the South Asian nation will need at least 500

aircraft in the 80- to 146-seat range over the next 20 years.