July 20 (Reuters) - The head of Embraer's planemaking unit said on Wednesday it expects to select an engine in the fourth quarter for a potential new turboprop plane that the Brazilian company expects to launch in early to mid-2023.

Embraer Commercial Aviation Chief Executive Arjan Meijer said the company is talking to Raytheon Technologies unit Pratt & Whitney Canada and to Britain's Rolls-Royce about engines for the project.

The third major engine maker in the market, General Electric Co, is not offering an engine, he added in an interview.

GE was not immediately available for comment.

Meijer said Embraer has letters of intent for "250-plus" aircraft from a broad slate of regions and types of operator, adding: "I underline 'plus'."

Embraer has been discussing returning to the turboprop sector since 2017 as it looks to expand its portfolio.

It said in 2020 it could opt for a combination of industrial and financial backing, though some analysts expect a more traditional approach based on risk-sharing deals with suppliers.

Turboprops are said to be more efficient on shorter trips and are particularly attractive at a time of higher oil prices.

The market is currently dominated by Franco-Italian ATR , which has announced plans to switch to upgraded engines provided by Pratt & Whitney Canada.

Embraer, last year unveiled its concept for the turboprop featuring engines mounted at the rear of the aircraft, an unusual change from the more conventional wing-mounted engines. (Reporting by Tim Hepher; editing by Jason Neely and David Gregorio)