PITTSBURGH, Pa., Sept 25 (Reuters) - U.S. Vice President

Kamala Harris said on Wednesday she would offer tax credits to

domestic manufacturers and invest in sectors that will "define

the next century", as she detailed her economic plan to boost

the U.S. middle class.

Speaking at the Economic Club of Pittsburgh in the

battleground state of Pennsylvania, the Democratic candidate in

the Nov. 5 presidential election said she would give tax credits

to U.S. manufacturers for retooling or rebuilding existing

factories and expanding "good union jobs," and double the number

of registered apprenticeships during her first term.

Harris also promised new investments in industries like

bio-manufacturing, aerospace, artificial intelligence and clean

energy.

Harris' speech, which lasted just under 40 minutes, did not

detail how these policies would work. She highlighted her

upbringing by a single mother, in contrast with Trump, the

wealthy son of a New York real estate developer.

"I have pledged that building a strong middle class will be

the defining goal of my presidency," Harris said, adding that

she sees the election as a moment of choice between two

"fundamentally different" visions of the U.S. economy held by

her and her Republican opponent Donald Trump.

The vice president and Trump are focusing their campaign

messaging on the economy, which Reuters/Ipsos polling shows is

voters' top concern, as the election approaches.

The divide between rich and poor has grown in recent

decades. The share of American households in the middle class,

defined as those with two-thirds to double that of median

household income, has dropped from around 62% in 1970 to 51% in

2023, Pew Research shows. These households' income has also not

grown as fast as those in the top tier.

Trump, Harris said, is "only interested in making life

better for himself and people like himself, the wealthiest of

Americans."

She said she was committed to working with the private

sector and entrepreneurs to help grow the middle class. She told

the audience that she is "a capitalist" who believes in "free

and fair markets," and described her policies as pragmatic

rather than rooted in ideology.

Harris in recent months has blunted Trump's advantage on the

economy, with a Reuters/Ipsos poll published on Tuesday showing

the Republican candidate with a marginal advantage of 2

percentage points on "the economy, unemployment and jobs," down

from an 11-point lead in late July.

Trump discussed his economic plan in North Carolina on

Wednesday and said Harris' role as vice president gave her the

chance now to improve the economic record of the Biden

administration.

"Families are suffering now. So if she has a plan, she

should stop grandstanding and do it," he said.

While Trump has proposed across-the-board tariffs on

foreign-made goods - a proposal backed by a slim majority of

voters - Harris is focusing on providing incentives for

businesses to keep their operations in the U.S.

Boosting American manufacturing in industries such as

semiconductors and bringing back jobs that have moved overseas

in recent decades have also been major goals for Biden. The

Infrastructure Investment and Jobs Act, the CHIPS and Science

Act, and the Inflation Reduction Act - all passed in 2021 and

2022 - fund a range of subsidies and tax incentives that

encourage companies to place projects in disadvantaged regions.