Managers of private-equity and other investment funds would see a majority of their taxes more than double under a multibillion-dollar jobs package being readied by Democrats that also extends soon-to-expire safety net programs.

The far-reaching bill, which was trimmed by Democrats in an effort to gain support this week, would extend unemployment and other benefits for hundreds of thousands of Americans, tighten tax rules for multinational companies and renew a set of popular business tax breaks that expired last year.

The House is set to take up the bill Thursday. Below is a summary of the latest version's key provisions. All cost estimates are preliminary and over a decade.

Fund Manager Taxes

The tax would hit the typical 20 percent share of profits that fund managers reap for managing money, known as "carried interest."

Fund managers, who can earn millions of dollars in a good year, pay a long-term capital gains tax rate of only 15 percent on their share of profits.

The bill proposes to treat 75 percent of those profits as ordinary income, a 35 percent tax rate for the highest earners. Until 2013, 50 percent of the profits will be treated as ordinary income.

The tax change would hit managers of private-equity, venture-capital, real-estate and hedge funds.

The provision has passed the House three times, but has yet to gain traction in the Senate. The issue has gained momentum in recent months, likely spurred by anger at Wall Street pay in the aftermath of the financial crisis.

The bill also slaps a 40 percent penalty on those caught attempting to skirt the taxes.

It would raise $19 billion for the government over the next 10 years, according to the nonpartisan Congressional Budget Office.

Unemployment, Health Benefit Extensions

A cornerstone of the bill is extension of unemployment and COBRA health benefits for the jobless, which are set to expire at month end. It keeps those benefits up and running until after election day, Nov. 30. With the unemployment rate stuck near 10 percent, backers argue that the extension is needed to keep millions out of poverty and point out that the money will be quickly circulated into the economy.

The total cost is $45 billion over 10 years.

Summer Jobs

The bill would pay for over 300,000 summer jobs for people aged 14 to 24, who have some of the highest unemployment levels. The total cost is $1 billion.

Medicare Doctors Pay

The legislation prevents a 21 percent cut in payments to doctors who treat patients on Medicare, the federal health insurance program for about 45 million elderly and disabled.

Known as the "doc fix," the provision could also be a sweetener given the constituency, though the projected cost of tens of billions of dollars has conservative Democrats grousing. AARP, the influential seniors' lobby group, is urging lawmakers to approve the package.

To gain backing of fiscal conservatives, Democrats trimmed the patch to about 1-1/2 years compared with a prior 3-1/2 years. The total cost is $22 billion over 10 years.

Foreign Tax Provisions

The bill tightens tax rules for multinational companies to raise about $14 billion. The biggest change would prevent companies keeping income offshore, while at the same time using foreign tax credits to cut their reported income in the United States.

Business Tax Breaks

The bill renews a set of popular tax breaks for business and individuals, the biggest being the research and development tax credit used by major Fortune 500 companies. Other benefits extended include a tax credit for the use of biodiesel and renewable diesel and accelerated depreciation for certain business improvements. The total cost is $32 billion.

Oil Companies, Spill Cleanup

The bill would boost the amount oil companies pay into a trust fund that pays economic damages from oil spills, to 34 cents a barrel from the current 8 cents a barrel.

The bill would also raise the $1 billion per incident limit on certain claims against the federal Oil Spill Liability Trust Fund to $5 billion. The fund was authorized for use in the aftermath of the Exxon Mobil Valdez spill.

Build America Bonds

The bill would extend the taxable Build America Bonds, created in the stimulus plan passed last year, for two years but lower the federal subsidy from 35 percent to 30 percent.

A total of $102 billion of the bonds have been sold so far, financing infrastructure projects across the nation. The total cost is $4 billion.