Dublin-based Taleo Corp., a maker of software used to hire and evaluate employees, may spend as much as $50 million to acquire companies with comparable technology, Chief Executive Officer Michael Gregoire said.

Taleo, whose clients include JPMorgan Chase & Co. and Starbucks Corp., spent $128 million last year to buy competitor Vurv Technology Inc., Gregoire said in an interview Friday. To finance buyouts, Taleo would use some of its $62 million in cash and might seek an equity or debt offering if more were needed, he said. Taleo has no long-term debt.

Social sites

San Francisco-based Twitter Inc., the social-networking service that lets users post 140-character messages, said its Web site is recovering from an outage Monday and that it's looking into what caused the disruption. Hackers attacked Twitter, Facebook Inc. and LiveJournal Inc. earlier this month by flooding the sites with requests, causing them to slow down or crash. Twitter shut down entirely Aug. 6, and users had problems sending updates the next day. Twitter had 20.1 million U.S. users in June, according to ComScore Inc. It ranks behind Facebook and News Corp.'s MySpace in social-networking users.

Online search

Although it plans to lean on rival Microsoft's search engine, Sunnyvale-based Yahoo says it will keep innovating in the field. That's one of the

main messages that Yahoo tried to convey Monday as it previewed an upcoming overhaul to its search page. Yahoo also unveiled a long-planned change that will bring more applications and information from other Web sites into its widely used e-mail service. The upcoming changes to Yahoo's search engine will include a feature that will let users look at results from social hubs such as Facebook and Twitter directly on Yahoo's results page. The new look is expected to be unveiled by the end of the year.

Oil

San Ramon-based Chevron Corp. said a compressor in the isomax unit at the Richmond refinery that malfunctioned and was taken offline last week has resumed operations.The 240,000 barrel-a-day plant had an equipment failure that caused more than 500 pounds of sulfur dioxide to be released last week, Chevron said in a filing with state regulators.

Compiled from staff and wire reports. Got Bay Area business news? Reach Drew Voros at 925-943-8099 or dvoros@bayareanewsgroup.com.