A joint venture of Boeing Co (BA.N) and Lockheed Martin Corp (LMT.N) plans to announce on Wednesday that it will team up with Blue Origin, a company run by Amazon.com Inc (AMZN.O) founder Jeff Bezos, to develop a new rocket engine, a source familiar with the plans said. Officials at Boeing and Lockheed declined comment. No comment was immediately available from Blue Origin or United Launch Alliance (ULA), the Boeing-Lockheed venture that uses Russian-built engines to power some of its rockets.