Measure H is designed to ensure that property transfers through corporate mergers and acquisitions are taxable in the same manner as other property transfers in Oakland.

It would not change the transfer tax rate of 1.5 percent, which is applied to home sales and other property transfers. It would seek to close what Measure H supporters call a loophole in the tax code that has left it unclear whether Oakland can collect the tax on certain types of large corporate deals.

Opposing the measure is the Oakland Metropolitan Chamber of Commerce. Advocates for seniors, libraries, public safety and organized labor support it.

Scott Peterson, the chamber's public policy director, said a no vote on Measure H would be a vote in favor of a business-friendly Oakland.

"Anything we can do to make Oakland more attractive to business is important," he said. "Whether that's growing our own local enterprises or attracting new companies to relocate here, every little bit helps."

He said the proposed change could particularly discourage emerging industries such as green technology and biotech from coming to Oakland. Supporters of the change don't buy it, and counter by saying the measure is designed to ensure fairness: that corporations pay the same tax rate as homeowners and small-business owners.

"The question for you to ask is: 'What's fair?'"‰" said Sharon Cornu, executive secretary-treasurer of the Central Labor Council of Alameda County. "This is a fair-share plan."

Estimates on how much the city might gain financially vary widely.

City Auditor Courtney Ruby's office, while acknowledging the difficulty of predicting corporate activity, used data from a four-year period beginning in 2003 to suggest as much as $4.4 million a year could be collected. An estimate this year from city staff members suggested revenues could be from $500,000 to $1 million annually. Peterson said it is impossible to tell whether that much would hit city coffers.

A simple majority is needed for the measure to pass.

— Kelly Rayburn