April 25 (Reuters) - Cincinnati Financial posted a rise in first-quarter profit on Thursday, helped by a jump in premiums and higher income from investments.

Earned premiums were up 8% at $2.07 billion for the quarter ended March 31. The company posted an adjusted operating income of $272 million, or $1.72 per share in the first-quarter, up from $141 million, or 89 cents, in the year-ago period.

Growing expectations of a soft landing for the U.S. economy fueled a rally in equities and other asset classes at the start of the year, helping insurers rake in more income from investments.

Cincinnati Financial's investment income, net of expenses, rose 17% to $245 million in the January to March quarter from a year ago.

Insurance bellwether Travelers Companies also posted a 28% jump in net investment income in the first quarter.

Cincinnati Financial offers a range of insurance products, including property and casualty insurance for individuals, businesses, and organizations.

(Reporting by Pritam Biswas and Mehnaz Yasmin in Bengaluru; Editing by Sriraj Kalluvila)