By Irene Klotz

CAPE CANAVERAL, Fla., July 23 (Reuters) - An upgraded Delta 4 rocket delivered a $445 million U.S. military communications satellite into orbit on Thursday, the seventh member of a planned network of 10 satellites.

Built and flown by United Launch Alliance, the 22-story tall booster rocket lifted off from Cape Canaveral Air Force Station at 8:07 p.m. EDT (0007 GMT).

United Launch Alliance is a partnership of Lockheed Martin Corp and Boeing Co. The Delta 4 was powered by an engine made by Aerojet Rocketdyne Holdings Inc.

Poor weather in Florida delayed the launch by one day.

Perched on top of the rocket was the U.S. Air Force's seventh Wideband Global Satcom (WGS) satellite, part of a network being built by Boeing.

Once in position more than 22,000 miles (35,400 km) above the equator, the satellite, known as WGS-7, will join a constellation that provides the military's highest capacity communications service. The 7,600-lb (3,447 kg) spacecraft is designed to last 14 years.

The WGS network is used to relay television broadcasts, video conferences, images and other high-bandwidth data to and from ships, aircraft, ground forces, operations centers, the U.S. Department of State, the White House and select partners worldwide.

In an unusual partnering arrangement with the U.S. Air Force, Australia paid $707 million for the WGS-6 satellite, which was launched in 2013. In exchange, Australia can use a percentage of the WGS network through 2029, when its 22-year agreement with the Air Force expires.

The Air Force has a similar agreement in place with Canada, Denmark, Luxemburg, Netherlands and New Zealand, which are banding together to pay for the ninth WGS spacecraft.

The U.S. military has not yet finalized partners to finance follow-on satellites, said Air Force spokeswoman Christina Greer.

(Reporting by Irene Klotz; Editing by Lisa Shumaker)