The Philadelphia 76ers finally obtained Moses Malone from the Houston Rockets yesterday after two weeks of contract haggling. The 76ers gave up their starting center, Caldwell Jones, plus a first-round draft choice, acquired from Cleveland, that could be the No. 1 pick in the next draft.

The possibility of drafting either Ralph Sampson, the 7-foot-4 all-America center from Virginia; Pat Ewing, Georgetown's 7-footer, or Sam Bowie, Kentucky's 7-footer, swung the deal for the Rockets.

Houston General Manager Ray Patterson is extremely impressed with Ewing, who is only a sophomore, and hopes that the shot-blocking center will apply for the draft next spring. Sampson and Bowie are seniors.

"If only Sampson were available it would be a gamble," Patterson said, referring to the coin flip between the last-place teams in the Eastern and Western Conference for the top pick. "However, the possibility of picking Sampson, Ewing or Bowie makes it that much more attractive."

Cleveland finished last in the East with only 15 victories last season and has not made any deals to strengthen its team. The 76ers were reluctant to give up the choice, offering either or both of their other first-round picks (New Jersey's and their own), but Patterson insisted on Cleveland's selection choice.

"We really had no other choice," Houston Coach Del Harris said of the trade, which was forced when Philadelphia signed Malone to a $13.2 million (over six years) offer sheet Sept. 2. The Rockets had 15 days, or until Saturday, to either give up Malone, match the offer and trade him or match the offer and pay an annual salary of $1.6 million, plus a $1 million signing bonus -- all in cash.

"When you lose a superstar," Harris continued, "you at least want a chance to get another superstar." The coach added that if the Rockets can draft an outstanding center, Jones, a 10-year veteran who averaged 8.7 rebounds a game, could easily be shifted to forward. Elvin Hayes, the Rockets' power forward, recently signed a two-year contract.

"Giving up that pick was just a gut-wrenching decision," General Manager Pat Williams of the 76ers said at a Philadelphia news conference. "We hated to do it, but Houston wanted to get something."

Malone, 28, flew to Philadelphia for the press conference and said: "I think coming here will make me a better ballplayer because people won't be looking at me to do everything. I'm just going to do what I do best."

What Malone does best is rebound and score. He led the league in rebounding last season for the third time (14.7 per game). His scoring has improved in each of his six seasons and last year he was second behind San Antonio's George Gervin with a 31.1 average.

Several clauses in the 76ers' offer sheet were disputed by the league, but last night, the NBA announced its approval of the trade.

"Commissioner Larry O'Brien has approved the trade . . . involved that of the five challenged provisions . . . two will remain and the three which were of most concern to the commissioner will be deleted," the statement said.

Malone will be allowed to receive $100,000 in outside endorsements and a bonus each year in which Philadelphia's home gate revenues exceed $4 million. The league will disallow bonuses if the 76ers are not among the top six in road attendance, if their home gate revenue is less than $3 million in any year and if they do not have a statistical leader other than Malone.