From the U.S Football League's first week of play to its fourth, both attendance and television ratings have dropped by more than half. Yet Commissioner Chet Simmons said yesterday the new league has enjoyed financial success beyond its original expectations.

In its first weekend of play, 204,718 fans attended USFL games and ABC's opening broad-casts had a 14.2 rating. Last Sunday, 86,587 people attended, and the network had a 6.4 rating.

"We've had tremedous competition with the NCAA basketball. But after baseball has had a chance to get started, I think we'll get past a seven (rating) or more," Simmons said. "Last week we got hammered on attendance, but all six of our markets got rained on or snowed on."

Federals owner Berl Bernhard said the opening weekend's figures were "beyond expectation" and relied heavily on "the novelty factor."

"I never thought we'd get those numbers for the first week, so when we went down 50 percent, it was with those first, big numbers in mind," Simmons said.

Jim Spence, the senior vice president of ABC Sports, had originally projected a 5-to-6 rating for the network's weekly USFL broadcasts. ABC bought the rights to the new league's games on the basis of that projection.

"We anticipated the dropoff," said Bernhard. "Everyone anticipated that the NCAA basketball tournament and the beginning of baseball season would be competition for the entertainment dollar. But eventually the NCAA goes away and the interest in baseball fades a little until the pennant races."

Although 38,010 people sat in the rain through at least part of the Federals' home opener against George Allen's Chicago Blitz, Washington fans were less willing to endure similar storms at the Michigan-Federals game Sunday. Of the 21,819 people who purchased tickets, only 11,423 showed up.

"You'd have to be a little bit crazy to sit outside in that kind of rain," Bernhard said.

Bernhard said he had made a preseason projection of 26,000 as an average "break-even" attendance. "So far we have that, and I think we'll continue to get at least that as the weather gets better," he said.

When the owners meet next week in Chicago, the topic of expansion will head the agenda. Three or four owners have expressed reservations about adding new teams, said Bernhard, who favors immediate expansion.

Although the league owners in the beginning of the season had been in nearly unanimous agreement about expanding the USFL from 12 to 16 teams next year, the issue is now coming under debate. Allen, who is chairman of the board and coach of the Blitz, has said the league should wait at least until 1985 to expand.

"Frankly I'm not interested in what George Allen has to say about expansion," Simmons said. "We're committed to it."

The leading cities for new franchises so far are Dallas, Houston and Pittsburgh. Minneapolis, Atlanta, and New Orleans also are under consideration. Simmons named San Antonio, Indianapolis, Memphis and Jacksonville as possibilities for the more distant future.

The New Jersey Generals' winless record has been a cause for concern among the owners. Certainly Herschel Walker's unspectacular performances on ABC's opening broadcasts did little to justify the hoopla and controversy surrounding his signing.

Further, any league, established or not, benefits financially from having successful teams in the New York metropolitan area. The Generals are the league's only 0-4 franchise.

"It doesn't help us and it certainly doesn't help the league with the start we've had," said James Valek, Generals vice president and general manager.

"There's bound to be disappointment. It has a real impact on us when the New York franchise doesn't do well," Simmons said. "The team was on television three weeks running, and the public saw New Jersey playing not very exciting football."

But Simmons insisted the league, as a whole, was healthy: "Some owners think they may break even or even make a little money the first year. Others stand to lose between $1 million and $2 million. It runs a spectrum.

"But generally we're doing well. We have a game in Tampa Bay Saturday night against the Blitz, and they're expecting 50,000. As long as the weather gives us a break, we'll be fine."