Al Davis, managing partner of the Oakland Raiders, was portrayed today as a man so driven by greed and ambition that he recklessly sought to break league rules and the hearts of Raider fans to move the team to the lucrative Los Angeles market.

The description came during the second day of the antitrust trial in U.S. District Court here as attorneys for the National Football League and other defendants made their opening remarks.

No sooner had the trial ended for the day that a commissioner for the Los Angeles Memorial Coliseum announced he had a good proposal by an investor to finance an expansion team for Los Angeles. Asked about this development, a spokesman for the NFL said that Commissioner Pete Rozelle might consider a deal without Davis.

Tuesday, attorneys for coplaintiffs Davis and the L.A. Coliseum accused the NFL and otherrs of violating the Sherman Antitrust Act by conspiring to block the Raider move to Los Angeles.

"What this case is about is money and power, and a man who doesn't want to live by the rules," said Joseph Cotchett, an attorney for Georgia Rosenbloom Frontiere, the owner of the Rams.

Frontiere is accused of conspiring with Rozelle and San Diego Charger owner Eugene Klein to keep the Raiders out of the Southern California market.

Patrick Lynch, chief attorney for the NFL, characterized the antitrust case as a complete fabrication. Instead, said Lynch, the law of contracts is what this case is about because, he said, Davis' move would violate the NFL constitution which, as an owner, he has agreed to uphold.

Plaitiffs' attorneys had argued that Davis is a hostage of the Oakland Coliseum and has been unfairly blocked from moving to Los Angeles, where he could earn a decent profit for himself and the Raiders.

Lynch said today, however, that evidence in the case would show that the Raiders are spectacularly successful as a business, describing Oakland as the fourth or fifth most profitable team in football.

The NFL attorney said that the Los Angeles Coliseum had made a secret deal to lure Davis to Los Angeles. The Coliseum has promised Davis $4 million of taxpayers' money to move, and about $2 million of this was to be used to finance a house for Davis in Beverly Hills, Lynch claimed.

Whatever the type of deal, it was frustrated by a series of court actions by the NFL.

The Coliseum filed suit against the NFL in 1978 after the Rams announced they were moving to Anaheim, some 25 miles away.

Cotchett said today that Frontiere's late husband, Carroll Rosenbloom, decided to move the Rams because the Los Angeles Coliseum Commission had for years refused to modernize the nearly 60-year-old stadium.

The Coliseum then turned to the NFL, but the league replied that Los Angeles would have to join other cities seeking expansion clubs. That was when the commission made a deal with Davis to bring the Raiders southward.

The Coliseum and Davis contend that Rule 4.3 of the NFL Constitution, which says a team cananot move without approval of three-quarters of the other 27 team owners, in unreasonable restraint of trade.

Peter F. Schabarum, a member of the Los Angeles County Board of Supervisors, said that theater entrepreneur James Nederlander has made a firm proposal to finance a new team for the city.

Stating that the commission's loyalty to coplaintiff Davis was ill-placed and unwarranted, Schabarum said that the commission should seriously consider this or another proposal. "If we win the suit . . . all we have is Davis," he said. "If we lose, we are dead. How can we expect the NFL to turn around and give L.A. a franchise."

However, for the commission to meet and consider such an offer, five of nine commissioners must agree, and Schabarum allowed that he had only two others lined up so far.