Jet engine maker Pratt & Whitney spent much of last year fighting to shut two engine repair shops in Connecticut due to fierce competition and the recession.

Now the economy is recovering, orders are rising for a marquee product and a competitor has been eliminated for a military fighter jet engine.

As a result, business is booming for the East Hartford-based subsidiary of United Technologies Corp.

In the last five weeks, three significant deals have been announced: an order for 300 of Pratt & Whitney's next-generation engines from Indian budget airline IndiGo, 30 engines for Lufthansa and 60 engines for Airbus planes purchased by International Lease Finance Corp., a subsidiary of American International Group.

"The backlog keeps getting bigger," Pratt & Whitney President David Hess told reporters last month.

United Technologies, headquartered in Hartford, has spent $1 billion over 20 years to develop its geared turbofan jet engine.

Pratt & Whitney, which says the engine generates fewer carbon emissions, cuts airlines' fuel costs and produces less noise than other airplane engines, "hung the future" on its product, said Matt Collins, an analyst at Edward Jones.

"They've proven they can win the orders for the geared turbofan and now they need to deliver," he said.

Pratt & Whitney also was the beneficiary of a decision by Congress last month to halt production of an alternate engine developed by General Electric Co. As a result, Pratt & Whitney is the sole manufacturer of the Pentagon's F-35 Joint Strike Fighter jet engine. Projected revenue will double by 2020 and employment in Connecticut is expected to hold steady, Hess said. The situation is a far cry from September 2009 when Pratt & Whitney, citing a downturn in the aerospace industry, announced plans to move jobs to Columbus, Ga., Singapore and Japan.