WASHINGTON — From their years at Harvard Law School to their tenure in the House of Representatives, Barney Frank and Christopher Cox chose markedly different approaches to reach their destinations.

This week, their paths will cross again as Rep. Frank, a Massachusetts Democrat, assumes control of the House Financial Services Committee, which oversees the Securities and Exchange Commission—led by Mr. Cox, a former Republican lawmaker from California.

Despite similar resumes, the men could hardly be more divergent in ideology and personal style.

Mr. Frank, who used an antineatness slogan in his first federal campaign 27 years ago, has a lacerating wit. His support for predatory-lending reforms, minimumwage increases, and universal health care mark him as one of the most left-leaning lawmakers on Capitol Hill.

Mr. Cox rarely appears in public with a hair out of place or a wrinkle in his perfectly tailored suits. He speaks with deliberation and labors to defuse criticism. Mr. Cox cut his teeth in the Reagan White House, and his votes in Congress earned him an 87% lifetime rating from the U.S. Chamber of Commerce before he became chairman of the Securities and Exchange Commission.

Already, they have clashed over a change to an SEC rule that some investor advocates say will reduce disclosure of executive pay in the form of certain stock awards. The change, announced in a press release three days before Christmas, amounted to a gift to the business lobby, Mr. Frank told reporters last week. “I didn’t even know they had a chimney at the SEC,” Mr. Frank joked, true to form.

Equally in character, Mr. Cox called Mr. Frank to smooth things over, explaining the timing of the move and defending his approach as logical, since, he said, the initial plan would have forced companies to report pay that corporate officials might never have collected.

The damage-control effort appears to have worked, for now. In a follow-up interview, Mr. Frank praised the SEC leader for his “responsible” approach at the helm and predicted few sharp disagreements to come. “There are going to be cases where I’ll believe we should go further than he,” said Mr. Frank, who advocates more disclosure to investors.

Mr. Frank was to present his agenda — what he calls “the grand bargain” — at the National Press Club this week. He is urging lawmakers to offer business concessions on trade and some burdensome regulations in exchange for more housing for the poor and minimum-wage gains.

For years, Mr. Frank has focused on housing and income inequality, just as Mr. Cox has championed making it easier for companies to win access to capital markets. But while holding fast to those priorities, neither has been reluctant to entertain opposing views.

To date, Mr. Cox has pursued a far less ideological agenda at the SEC than governance analysts expected — and Mr. Frank’s record reflects a more business-friendly stance than many have anticipated. Both men voted in favor of a 1995 law that imposed limits on the filing of class-action securities lawsuits. While in Congress, both reaped significant campaign contributions from banks, insurers, and law and accounting firms. And both have said they turn first to the markets for solutions to economic problems, rather than to government.

Mr. Frank, for instance, said he agrees with certain conclusions reached late last year by an independent panel with support from Treasury Secretary Henry Paulson Jr., including making it more difficult for prosecutors to indict businesses. He also supported tweaks to a costly audit rule springing from the 2002 Sarbanes-Oxley law, as long as the intent of the corporate accountability legislation was not thwarted.

“They’re both pragmatic,” the director of investor protection at the Consumer Federation of America, Barbara Roper, said. “I don’t think either of them is looking to pursue a radical agenda.”

But, as the SEC leader learned last week, Mr. Frank is less flexible in the area of ever-expanding executive pay — an issue that fits into his broader agenda of lessening wealth disparity and one he says could come up for Financial Services hearings as early as March, after he holds oversight sessions on housing problems stemming from Hurricane Katrina. Mr. Frank previously introduced legislation that would put executive compensation up for a shareholder vote, a measure he is likely to revisit this year.

Mr. Frank’s sister, Ann Lewis, a campaign adviser to Senator Clinton.

“He has certainly been eager for Democrats to have the responsibility for governance,” Ms. Lewis said.

She says her brother developed a thick skin after years growing up in Bayonne, N.J., and playing in the sometimes brutal fields of Boston politics.

He leavens that intensity with humor to disarm his audience and make a point, which Ms. Lewis said “really goes a long way to enabling him to be politically effective.”

Mr. Cox, by contrast, earnestly strives to reach consensus, making unanimous votes a priority at an agency that had been sharply divided under his predecessor. A series of 5 to 0 votes last year at the SEC is a testament to Mr. Cox’s political acumen and also makes the agency a less attractive target for Hill Democrats, the consumer federation’s Ms. Roper said.

That’s an observation Mr. Frank agrees with. “Chris is a lawyer, and he’s a very careful guy,” he said. “Among other things, he understands he’s a law enforcement officer.”