US Airways Group and the Nutter administration, which have disagreed publicly about the need for a new runway along the Delaware River, announced Tuesday terms of a two-year lease extension for Philadelphia's dominant airline that allows for $734 million in capital investment at the airport.

The agreement does not include building a controversial fifth runway on the river and displacing United Parcel Service from 212 acres it owns.

The city and US Airways, in a joint statement, said they had agreed to:

Lengthen a main east-west runway by 1,500 feet, from 10,500 to 12,000 feet, to accommodate large, long-haul aircraft capable of flying anywhere in the world.

Redesign the Terminal B and C ticketing areas, with new, automated baggage handling and screening and a centralized, spacious passenger-security checkpoint.

Replace current rental-car surface lots with a multistory, consolidated rental-car building.

Design an automated "people mover" train between the concourses, making it easier for passengers to connect to flights.

Improve taxiway and aircraft-holding areas on the airfield to queue planes better for departure.

Make security upgrades, roof and window replacements, and improvements to escalators, restrooms, roadways, concessions, and flight-information displays.

"This agreement facilitates the continuation of our partnership to move forward with the projects that are crucial to the airport and the region," Mayor Nutter said.

The statement said the projects would positively affect the region's economy and create jobs and construction opportunities.

US Airways' chief executive officer, Doug Parker, said: "With the mayor's leadership, we have reached agreement on the near-term completion of projects critical to the continued improvement of US Airways operations and customer service at PHL, as well as a playbook for pursuing the long-term development of the airport."

The city and US Airways pledged "to continue working together on identifying areas of mutual agreement" that advance the airport's longer-term expansion "in a responsible manner and support the vitality of this great region," the statement said.

Everything agreed to by the city and US Airways is part of a massive expansion of the airport through 2025.

The city has estimated that the total cost would be $6.4 billion. The airlines, which would bear much of the expense, say that the price would be much higher, about $10.5 billion, and that it could force them to reduce operations in Philadelphia. A project manager has been hired to assess the actual costs.

US Airways' lease to use the airport was to expire in July. The lease extension runs through June 30, 2015.

The lease extension gives the airport and US Airways two more years to assess the cost and need for a fifth runway. And it will provide more time to see whether aircraft operations (takeoffs and landings) at Philadelphia airport pick up, remain flat, or decline.