Bridgestone Americas plans to invest $74 million more through next year to expand its Firestone tire factory in Des Moines.
The Des Moines Register reports the investment is in addition to Bridgestone's $77 million project at the plant, which was announced in March 2010.
The plant has added about 250 workers in the past two years, bringing the total to nearly 1,700 people. Bridgestone Americas, which is based in Nashville, Tenn., didn't say whether the new plan will bring more jobs.
The plant makes tires for the agricultural, forestry and construction equipment markets.
The state and Polk County gave Bridgestone $600,000 in loans and grants, plus $108,000 in tax credits, last year to aid the last expansion.
Officials say Bridgestone hasn't applied for assistance with its latest expansion plan.