company rival, the Westinghouse Electric & Manufacturing Corporation, had also purchased rights to some critical patents, including one for heterodyne receiving originally issued to Reginald Fessenden, plus regenerative circuit and superheterodyne receiver patents issued to Edwin Armstrong. Westinghouse used this position to negotiate a cross-licensing agreement, effective July 1, 1921, that included a concession that 40% of RCA's equipment purchases would be from Westinghouse. Following these transactions, GE owned 30.1% of RCA's stock, Westinghouse 20.6%, AT&T 10.3%, and United Fruit 4.1%, with the remaining 34.9% owned by individual shareholders. In 1930, RCA agreed to occupy the yet-to-be-constructed landmark skyscraper of the Rockefeller Center complex, 30 Rockefeller Plaza, which in 1933 became known as the RCA Building (renamed the GE Building in 1988 and currently known as the Comcast Building after Comcast bought NBC-TV). This lease was critical for enabling the massive project to proceed as a commercially viable venture—David Rockefeler cited RCA's action as being responsible for "the salvation of the project". Radio development International and marine communication At the time RCA was founded in 1919 all radio and telegraphic communications between China and the US, including official communications, were run through either German radio or British cables. The U.S. Navy wanted RCA to seek a concession in China, however the company was reluctant to do so because their other concessions were already operating at a loss. With RCA's agreement the transmitter was completed in 1928, but when another American interest signed a similar agreement with China in 1932 RCA claimed breach of contract in Radio Corporation of America v China. RCA's primary business objectives at its founding were to provide equipment and services for seagoing vessels, and "worldwide wireless" communication in competition with the undersea cables. To provide the international service, the company soon undertook a massive project to build a "Radio Central" communications hub at Rocky Point, Long Island, New York, designed to achieve "the realization of the vision of communication engineers to transmit messages to all points of the world from a single centrally located source". Construction began in July 1920, and the site was dedicated on November 5, 1921, after two of the antenna spokes had been completed, and two of the 200-kilowatt alternators installed. The debut transmissions received replies from stations in 17 countries. Although the initial installation would remain in operation, the additional antenna spokes and alternator installations would not be completed, due to