AT&T, as Bell Labs, was a phone company that created the first working version of the transistor, a concept invented and patented by Julius Lilienfeld twenty years earlier.
But they were at the time, a technology company. Technology isn't defined by silicon and code, but by the fact that a company grows by inventing new things. Google may be on track to becoming an advertising company, but they seem damn resistant to the idea given how many of their new businesses they're burning through to find new revenue.