The promise of using algae to make biofuels — a dream scientists have chased for decades — might seem particularly welcome in a time of stubbornly high gasoline prices. But the path to commercial-scale production has been circuitous.

Young companies have attracted investors and interest, but as they struggle to make large quantities of ethanol and biodiesel at a competitive cost, some have branched out into making oils for products with higher profit margins, like cosmetics, food and soap.

Now, one of these companies, Solazyme, is about to take a step toward large-scale fuel production. On Tuesday, it will announce an agreement with Bunge Global Innovation to build a factory in Brazil that would make triglyceride oils for both chemical and fuel products.

Under the joint venture, whose financial terms were not disclosed, the factory would rise next to Bunge’s Moema sugar cane mill and have an annual capacity of 100,000 metric tons, or about 110,250 short tons, of oil. It would start production in the second half of next year, making oils for fuel as well as additives for soaps, detergents and plastics.

Ben Pearcy, a managing director of Bunge Ltd., a global agribusiness and food company, said in a prepared statement that the partnership would “enable us to link our sugar and vegetable oil value chains,” and expand the company’s reach in fuels and chemicals. For Solazyme, which has skin care and nutritional supplement lines, the arrangement provides a boost in production capacity “to meet the strong demand we’re seeing in our initial target markets,” said Jonathan Wolfson, the company’s chief executive.

So far, the company has produced only limited quantities of biofuels, including several hundred thousand liters to the United States military, which is seeking to promote alternatives to conventional fuels.

Solazyme, which is based in South San Francisco, Calif., bioengineers its algae so that it can convert sugars directly into oils without photosynthesis. This allows the organisms to be grown in fermentation tanks, which reduces the costs of a still-expensive process.

A competitor, Sapphire Energy, announced on Monday that it had secured $144 million from investors for its demonstration plant in New Mexico. Sapphire, which does use photosynthesis in its production process, has also received a $50 million grant from the Energy Department and a $54.4 million loan guarantee from the Agriculture Department, according to the company.

By DIANE CARDWELL

Ford Motor Co’s U.S. sales rose 5 percent from a year earlier. Ford, No. 2 in the U.S. market, reported its best March for new auto sales in five years on strong sales of small cars such as its Focus sedan and its F-Series pickup trucks.

Chrysler Group LLC, No. 4 in U.S. sales, reported a 34 percent increase, led by its Chrysler brand, which had a sales increase of 70 percent.

It was the 24th consecutive month that Chrysler showed a year-on-year sales gain.

Nissan Motor Co said its sales in March rose 12.5 percent, and Volkswagen AG said its March sales soared 35 percent — its the best U.S. March sales since 1973.

Other major automakers will report March sales later on Tuesday, and most expect significant increases.

For instance, South Korea’s Hyundai Motor Co, which has the best fleet-wide fuel economy ratings in the market, said it expected to have record monthly sales.

Consumer confidence rose in March to its highest level since February 2011, the Thomson Reuters/University of Michigan reading of consumer sentiment showed.

As sales rise — the first quarter is expected to come in as the best quarter since 2008 — automakers are also getting more profit per vehicle. Incentives continued to trend downward in March while the average transaction prices per new vehicle rose, autos consultant TrueCar.com said on Tuesday.

Auto analysts surveyed by Thomson Reuters expect an annualized sales rate for March of 14.74 million vehicles, which would be a rise from last March’s 13.1 million sales rate. Analysts say pent-up demand, easier credit, more fuel-efficient product offerings and mild weather helped boost March sales.

No. 1 in U.S. and global auto sales, General Motors Co is expected to show a rise in March sales of more than 20 percent over a weak March 2011, auto consultant Edmunds.com said.

Toyota Motor Corp, No. 3 in U.S. sales, is expected to post a rise of as much as 22 percent, Edmunds said.

Mike Jackson, chief executive of the largest auto retailer, AutoNation Corp, told CNBC on Monday that the company raised its 2012 sales forecast to about 14.5 million from 14 million, based on the strongest quarter for auto sales since before the sales downturn that began in late 2008.

By Bernie Woodall and David Bailey

A stream of new orders buoyed factory activity in China to an 11-month high in March, according to the official PMI, but credit-constrained smaller manufacturers struggled, suggesting the economy was still losing steam.

Three-month copper on the London Metal Exchange edged up 0.24 percent to $8,465 a metric ton in official midday rings from $8,445, with volumes at around 7,800 lots, a good level while Shanghai markets are closed from Monday to Wednesday for public holidays.

“The market had already discounted that small and medium (Chinese) companies are struggling. so the news that the biggest companies are doing slightly better than expected prompted some short-covering,” said Gianclaudio Torlizzi, analyst at metals consultancy T-Commodity.

But he added, “We don’t buy today’s move as the beginning of a bullish phase because we think the Chinese economy is still slowing down and at the same time the central bank is not yet willing to cut interest rates.”

Also capping gains in metals, the euro zone’s manufacturing sector in March shrank for an eighth month and at a faster pace, adding to signs the bloc is in recession as the downturn spreads to core members France and Germany.

Investor focus turned to the U.S. Institute for Supply Management manufacturing data due later in the day.

U.S. data released on Friday showed U.S. consumer spending increased by the most in seven months in February as households shook off a rise in gasoline prices, leading economists to raise forecasts for first-quarter growth.

“The U.S. ISM data today is likely to confirm economic stabilization once again. We think (metals) prices can stabilize and trade sideways this week,” said Credit Suisse analysts in a note.

They also pointed to falling stocks in China, where data showed a drop in Shanghai copper stocks in the past two weeks from near-decade high levels. LME stocks rose for the third time in about four session but remained near their lowest since July 2008.

LULLED

Price trends in copper, which is up about 12 percent this year as worries over the debt-strainedeuro zone have eased and the U.S. economy has begun to pick up, now mostly depends on China. The rate of slowdown in a country that consumes around 40 percent of the world’s copper will be key to whether the industrial metal will build on or erase its year-to-date gain.

“We should not be lulled into thinking that China has turned a corner … Global conditions continue to be highly uncertain, and given that China’s finished goods inventory has recovered quite steadily, room for further inventory building may be limited,” said Vishnu Varathan, a market economist at Mizuho Corporate Bank.

In other metals traded, aluminum fell 0.24 percent to $2,121 a metric ton in rings from $2,126, while stainless-steel ingredient nickel rose 0.42 percent to $17,900 from $17,825.

State-run Aluminum Corp of China Ltd (601600.SS) (2600.HK) agreed to pay $926 million for a controlling stake in Mongolian coal miner SouthGobi Resources in a deal with mining billionaire Robert Friedland’s Ivanhoe Resources.

The deal marks the first foray into coal by Chalco, which is facing a bleak outlook in aluminum, and will give it access to a large coal producer in neighboring Mongolia.

On nickel, which has risen just 1 percent in the year to date, making it the worst performing metal in the complex to date, analysts are turning decidedly more optimistic, saying the selling has been overdone given changing fundamentals.

“Feedback from the recent days suggests Chinese buyers (are) rushing to restock at what are believed to be low prices. This is reflected in rising physical spot premiums over the last week or so,” said Macquarie analysts in a note.

“The LME nickel price is now trading below domestic prices in China, which makes buying imports more attractive, and currently prevailing price levels are trading below cash production costs for some nickel pig iron production in China.”

Battery material lead fell 1.37 percent to $2,012 a metric ton from $2,040, soldering metal tin was little changed at $22805 from $22,800, while zinc, used in galvanizing fell 1.10 percent to a last bid at $1,979 from $2,001.

The latest LME data showed zinc stocks fell 550 metric tons but remained near their highest level in around 17 years at 896,825 metric tons. Analysts at Macquarie say zinc stocks sitting in warehouses not monitored by the exchange also are expanding as more of the metal is used for financing purposes.