Maurice R. Valente, who less than six months ago was named president of RCA Corp., was forced to resign today by RCA's board.

RCA Chairman Edgar H. Griffiths said the board decided unanimously that Valente's "performance over nearly six months did not meet expectations in terms of the company's long-range needs and objectives." But sources close to RCA said the ouster of the former International Telephone and Telegraph Corp. official had as much to do with Valente's personal behavior as with his performance during his brief tenure in the number two spot at RCA.

"That's absolutely untrue," an RCA spokesman said. "It simply had to do with his performance. The board unanimously decided to act after a careful evaluation." Asked how Valente's performance could be measured in such a short time, the spokesman said: "We're experts at that. It's easier to measure failure than success."

Valente, 51, was executive vice president of ITT when he was named to the post of RCA president and chief operating officer last November. He actually took the post on Jan. 1.

Valente's hiring ended a two-year search for an executive to fill the second post at RCA. Griffiths, who had been president and chief executive officer, became chairman and chief executive upon Valente's accession.

Today Griffiths said RCA -- which owns the National Broadcasting Co., and Hertz Corp., among other things -- would abolish the job of president and instead create a corporate structure in which five executive vice presidents will report directly to Griffiths, who is 59.

Valente's surprise ouster follows by six weeks a similar firing of the president of CBS Inc., and radio networks. But John D. Backe, unlike Valente, had been president of CBS for more than three years and seemed to be the heir apparent to long-time Chairman William Paley.

The abrupt firing of Backe shocked the business and financial community. Thomas H. Wyman, 50, who had been vice chairman of Pillsbury Co., became president and chief executive officer of CBS on June 2.

Although RCA has had some severe difficulties in recent months -- from NBC's loss of Olympic coverage because of the boycott to RCA's loss of a communications satellite several days after its launch last December -- none of them could be attributed to Valente.

Griffiths himself said that the management change does not relate in any way to the company's current performance. RCA has had three consecutive years of record earnings and continues to perform well in today's difficult economic climate."

A spokesman for RCA said that it was Valente's inability to fill RCA's long-run needs that led to his early and swift downfall.

"Although Griffiths will be only 59 on Monday, the company would like to have a successor around," the spokesman said. "Normally you could look to the number-two man as successor. But there was no way Valente was going to succeed Griffiths. It just was not going to happen."

Presumably Griffiths will remain chairman for another six years and find his successor among the five executive vice presidents in his new structure.

When Valente was named president Griffiths said that both NBC and Hertz would continue to report to the chairman directly. But Valente had control over the company's vast electronics and communications operations as well as its newest acquisition CIT Financial Corp.

Rumors continue to persist in the industry that Jan Cahill Pfeiffer, chairman of the NBC subsidiary, also will depart in the near future.NBC, despite the efforts of its so-called programming wizard, President Ford Silverman, remains mired in third place among the three major networks.

Sources say that Pfeiffer has little role in running the network because Silverman makes most of the important programming decisions.

Valente, who was told about his ouster on Monday, reached a financial settlement with RCA Tuesday, but the company said it would not reveal the details of that settlement until its normal annual filing with the Securities and Exchange Commission next year.