Complex sentence: The Radio Corporation of America or RCA, in an effort to compete, started modeling AT&T's network idea, but this proved difficult because RCA had to lease the phone lines from AT&T ultimately creating a conflict of interest.
Split into simpler sentences: The Radio Corporation of America or RCA, in an effort to compete, started modeling AT&T's network idea. But this proved difficult because RCA had to lease the phone lines from AT&T ultimately creating a conflict of interest.