* Signs $940 mln contract with U.S. leasing firm Aerolease
* Mitsubishi says no delay expected for delivery of first MRJ
* Sees growing interest from clients after test flight (Adds comments from executives)
SINGAPORE, Feb 16 (Reuters) - Mitsubishi Aircraft Corp, a unit of Mitsubishi Heavy Industries Ltd, has struck a deal to supply 20 regional jets to U.S. leasing firm Aerolease, its first agreement with a lessor.
The Japanese firm has struggled with multiple delays in its effort to enter the regional jet market, currently dominated by Canada's Bombardier Inc and Brazil's Embraer SA .
Mitsubishi said the letter of intent signed with Aerolease for the jets, worth about $940 million, would be converted into a definitive contract in the next month or so, lifting the total number of orders for the Mitsubishi Regional Jets (MRJ) to 427, including 233 firm orders and 170 options.
The company said it had seen increased interest from potential customers after its first flight test concluded.
"After the first flight, we feel the interest from potential customers is increasing," Hiromichi Morimoto, president of Mitsubishi Aircraft Corp, told reporters after announcing Aerolease's order at the Singapore Airshow.
Morimoto added that some potential clients in Asia Pacific had sent in detailed enquiries.
"Asia Pacific region is promising for us, for regional jets. We are right now working really hard on sales promotion in the Asia Pacific region," Morimoto said.
Morimoto did not expect further delays in the delivery of its first MRJ, which is slated for middle of 2018, after announcing late last year that the delivery would be pushed back for a year.
The $47 million, 100 seat MRJ, which made its maiden test flight in November, represents Japan's long-held ambition to re-establish a commercial aircraft industry.
"We have much more confidence than before," said Yugo Fukuhara, vice president and general manager of sales and marketing.
"Still, we still have a very big challenge, but I think we can overcome the challenge." (Reporting by Rujun Shen and Anshuman Daga; Editing by Muralikumar Anantharaman)