Consolidated Rail Corp., the federally subsidized freight railroad, yesterday put forth a five-year plan that eliminates any further federal investment beyond the already-authorized $3.3 billion.

However, the plan assumed that the federal government will act to reduce its regulatory hold over the railroad industry by 1981.

The new plan was submitted to the United States Railway Association, the government corporation created to provide funds for and monitor Conrail, the successor to bankrupt railroads in the Notheast and Midwest. The five-year business plans are required by the financing agreement.

At a press conference here, Edward G. Jordan, Conrail chairman and chief executive officer, noted that Conrail's current financial results are stronger than at any time since it was formed in April 1976. In the second quarter Conrail reported net income of $29.4 million, its first profit-making quarter.

Even though Conrail sees signs of economic conditions that make the next months less rosy, Jordan said the second-quarter results signaled a rebuilt physical plant and equipment fleet capable of providing adequate rail service.

But regulatory reform is the key, he said. "Although Conrail's prospects for meeting its legislated financial and service goals are considerably brighter, the corporation is still not in a position to predict confidently the achievement of a self-sustaining operation within the current regulatory environment," Jordan said.

If Conrail must continue to operate within the existing regulatory environment and additional financial burdens are imposed on Conrail by various governmental actions, there is a risk that large additional infusions of federal financing could be required he warned.

A Conrail plan submitted to USRA in March had warned that $782 million in government subsidies will be required to keep Conrail going through 1983 if Congress fails to deregulate the rail industry. It also said at the time that about $500 million of it could be avoided with substantial deregulation by 1980.

Now apparently taking the positive approach, Conrail yesterday projected net income of about $1.3 billion for the 1980-84 period on the assumption that regultory reforms are implemented by January 1, 1981.

Deregulation would allow the freight line to tailor its operations and alter its investment priorities in response to particular developing market opportunities, Jordan said.

Under the new plan -- assuming deregulation -- Jordan said Conrail expects to retain more than 90 percent of its current tonnage even though as many as 1,900 route miles might be dropped from the system as market dynamics show them incapable of being compensatory.

"The business plan has been formulated on the premise of fundamental regulatory reform because such reform offer the most promisng opportunity for Conrail -- and ultimately the entire rail industry -- to avoid becoming continuously dependment upon Federal funds in order to serve the nation's rail transportation needs," Jordan said.