Sen. Edward M. Kennedy (D-Mass.) took his liberal credentials before an audience of New York investment executives tonight, assuring them that he shares with them the goal of revitalizing the nation's economy.

"The goal we share is not to turn back the clock in nostalgia for a time gone by," Kennedy told the Investment Association of New York. "We do not ask to bring back the New Deal or restore the New Frontier to life. Instead, we seek to evoke a nobler spirit, adequate to these different and unruly times, to generate once again the 'can do' attitude that has always been the hallmark of America at its best."

Tonight's speech marked the beginning of a two-day trip by Kennedy, his first-since he announced that he may challenge President Carter for the Democratic presiddential nomination.

Kennedy mentioned Carter only once tonight, to praise the administration for negotiating the new trade agreement. But at the same time, he delivered a general indictment of the U.S. economic performance during the 1970s.

Kennedy, who has said his concern over the state of the U.S. economy has led him to consider running for president, proposed seven measures that he said would increase productivity and innovation in the economy. These included additional but unspecified incentives for capital investment, a revamping of the patent system and cooperative research programs among competing companies.

Earlier today in Washington, White House press secretary Jody Powell suggested that Kennedy cannot make up his mind on how to go about challenging President Carter for the Democratic nomination.

In the latest example of the political fencing between the White House and Kennedy, Powell said he had noted an "interesting pattern" over the last year, beginning with Kennedy's criticism of the administration for increasing defense spending while holding down funding for domestic social programs.

"We then found out a few weeks ago that there is no real difference over these issues and the issue was what happened to the economy in the next two months," Powell said. "Then we were informed that the issue was not the economy but leadership that should be talked about but the issues."

Earlier this year, Kennedy criticized some of Carter's budget proposals, saying that too much was being spent on defense. When Kennedy earlier this month announced that he was considering a presidential campaign, he said he would base his decision largely on the performance of the economy.

In later interviews, Kennedy also suggested that he could provide more effective leadership than Carter in managing the economy.

In an earlier interview, Powell said he understood what Kennedy and his supporters have been doing over the last few weeks.

"This shuffling is a process of deciding which issues they want to focus on," he said. "They're trying to figure out how best to posture themselves for a run for president."