With the credit market in shambles, oil prices pushing $150 a barrel and foreclosures mounting across the Southland, Wall Street has been less than kind to Los Angeles’ public companies over the past year.

The market capitalization of the county’s 200 largest publicly traded companies, as ranked by the Business Journal at midyear, dipped 18 percent since last summer to $415 billion the lowest total since 2004.

With few exceptions, industries across the spectrum suffered declines, and hints that the market has slipped into bear territory and the economy into a recession suggest there will be even tougher times ahead. Indeed, since last summer, more than 80 percent of local public companies suffered declines.

But there is still a silver lining.

Though many companies have been hit by rising energy costs, Occidental Petroleum Corp. has ridden the wave to riches. The Los Angeles-based oil and gas exploration company’s market cap surged more than 50 percent to a whopping $73.8 billion enough to land the company at the No. 1 spot on the list for the first time.

This marks the second consecutive year that a new company has ascended the rankings. Last year’s leader, Burbank-based Walt Disney Co., passed Thousand Oaks-based Amgen Inc., which had held the top spot every year since the Business Journal began ranking public companies in 2002.

But, like many companies on the list, each took considerable hits on Wall Street this past year. The entertainment behemoth, which landed at the No. 2 spot on the list, saw its market cap fall 12 percent to $59.4 billion amid the general decline in equities. Meanwhile, the stockholder value of the biotech company, which has been facing safety concerns about some of its leading drugs, fell nearly 20 percent to $51.3 billion dropping it to No. 3.

Of course, L.A.’s public financial companies took serious hits amid the upheaval in the housing and lending markets. Mortgage lenders such as Countrywide Financial Corp. which was acquired this month by Bank of America Corp. and IndyMac Bancorp Inc., as well as traditional commercial banks including First Regional Bancorp and Preferred Bank Los Angeles, each dropped more than 20 places on the list.

In total, 156 companies on the list saw their market caps fall, while just 36 increased their stockholder values. Eight companies completed initial public offerings in the past year and therefore had no market cap last year.

Yet, despite the declines, it could have been much worse.

Los Angeles has less exposure to the financial sector than many major cities, which has helped the region avoid a more serious decline, said Edward Wedbush, president of Los Angeles-based investment bank Wedbush Morgan Securities Inc.

“The market cap valuation declines among Los Angeles-headquartered companies is completely a function of the overall market decline, and Los Angeles has a relatively small percentage of the headquartered financial institutions compared to the rest of the country,” he said. “The other industries that are prime in Southern California particularly biomedical and so on they have been performing reasonably well. I see Los Angeles as positive.”

Black gold

One of the most positive sectors anywhere in the country has been oil.

And unlike most companies that have struggled with rising production costs in the face of high oil prices, Occidental has benefited. More than most of its peers in the oil and gas industry, Occidental is in a good position to take advantage of the high prices, analysts said.

“They have a very high leverage to oil 78 percent of their reserves are oil whereas many other domestic exploration and production companies are more heavily weighted toward natural gas,” said Cory Garcia, an analyst with Raymond James & Associates Inc. “Given where oil is at right now, that translates into a strong free cash flow.”

But whether the company can keep up its strong growth rate has been called into question. In a recent research report, analyst Benjamin Dell said Occidental’s balance sheet is beginning to see some strains.

“The company is facing increased competition for new assets, driving down returns,” said Dell of Bernstein Investment Research and Management Inc. “As such, the company’s stated growth will most likely require an acceleration of M & A; activity in the U.S.”

Recently, however, Occidental has been boosted by oil prices, and it’s not the only one: Breitburn Energy Partners LP and Pacific Energy Resources Ltd. each jumped up the list. Los Angeles-based Breitburn, which specializes in recovering hard-to-get oil, nearly doubled its market cap since last summer to $1.45 billion, bumping it up to No. 33 on the list from No. 77 in 2007. Long Beach-based Pacific Energy increased its stockholder value to $254 million, landing it at No. 92.

Though Southern California has benefited from oil exploration, it also, like many major cities, has struggled in the financial realm.

Of all the companies that declined in value over the past year, no sectors were hit as hard as financial, and no companies fell farther down the list than IndyMac.

The Pasadena-based mortgage lender plummeted 99 spots to No. 139, as its market cap fell to $63 million from more than $2 billion last year. The company, which has specialized in so-called “Alt-A” loans for borrowers with less-than-perfect credit, has become a poster child, along with Countrywide, for the mortgage meltdown. It is the target of multiple lawsuits alleging that the company engaged in deceptive lending practices.

Since last year, IndyMac’s stock has lost roughly 98 percent of its value and the company’s revenue has dropped to just $4 million from over $1.3 billion. And it could get worse. Last week the lender announced thousands of layoffs and the sale of 60 retail mortgage branches.

Like IndyMac, Countrywide’s value took a nosedive from write-downs the company took as a result of rising foreclosures. Countrywide dropped to No. 27 on this year’s list from No. 6 last year. The company’s acquisition by Bank of America closed July 1, ending it existence as a public company.

For the first time, no financial company cracked the top 20. But since most of Los Angeles’ public companies declined over the past year, some companies actually climbed the list while their market caps shrank. For example, CVB Financial Corp.’s market value dropped 15 percent to $784 million, but the regional bank actually jumped 17 spots to No. 52.

Another sector that has fallen, particularly in Southern California, is the real estate market. After years of strong growth, many companies dropped as the commercial property market began drying up and the housing market crumbled.

Commercial real estate services company CB Richard Ellis Group Inc. dropped four spots to No. 16 as its market cap declined more than 50 percent to $3.9 billion.

Likewise, homebuilder KB Home fell 12 spots to No. 38 as its market cap shrank more than 60 percent to $1.3 billion.

One of the few bright spots for the local market was aerospace. Despite years of decline in aerospace manufacturing, which was once a dominant local industry, several companies were boosted in the past year amid increased defense spending.

Monrovia-based Aerovironment Inc. (No. 65), which makes lightweight unmanned aerial vehicles for the military, jumped more than 30 spots on the list as its stockholder value climbed 44 percent to $561 million. Teledyne Technologies Inc. (No. 31) and Hi-Shear Technology Corp. (No. 128) moved up the list as well.

Large-cap exodus

Los Angeles lost some high-profile companies in the past year. The eighth-largest company on last year’s list, Hilton Hotels Corp., was acquired by New York-based private equity firm Blackstone Group LP. Computer Sciences Corp., which pulled down the No. 10 spot in 2007, has since moved its headquarters from El Segundo to Falls Church, Va.

And just last week, video game maker Activision Inc. No. 8 on the list with a $10.1 billion market cap joined Countrywide in the completion of its acquisition by a rival. French conglomerate Vivendi SA is combining its video game unit with Activision to create the world’s largest video game company, called Activision Blizzard.

Losing big public companies is nothing new for Los Angeles. From Hilton and Computer Sciences this past year, to WellPoint Health Networks in 2004, to SunAmerica in 1999, large companies have a history of leaving Southern California or getting snatched up by outsiders.

“We’ve been losing big companies, or they’ve been acquired, for a number of years,” said Dennis McCarthy, managing director of Los Angeles investment bank B. Riley & Co. “Our market here in Southern California is much more characterized by the many midsized companies that we have. We really are more of a midmarket area.”

California has a vibrant, but young, economy, he said, which caters to startups much more so than large, established companies. The state has a large knowledge base, sufficient demand for fresh products and a wealth of venture capital necessary to fund new companies.

But at the same time, he said, it is becoming increasingly difficult for mid- and small-cap companies to thrive in the public markets as individual investors avoid stock picking and seek the safety of big mutual funds managed by professionals.

“Nowadays you have to be fairly large in terms of market cap to attract investors,” he said. “Individual investors, who used to be the mainstay of these small-cap, midcap markets, have to some extent left the market.”