ROME, March 27 (Reuters) - Italian bank UniCredit and payments company Nexi have agreed on broad terms to renegotiate their existing working agreement, a person with knowledge of the matter said, confirming press reports.

Il Sole 24 Ore and MF newspapers reported on Wednesday that a revised accord would be signed later this year.

The deal will be adjusted under terms that are more satisfactory to UniCredit while also widening the markets in which the two companies collaborate, the source said, adding that it would be finalised in the next few weeks.

UniCredit and Nexi had no immediate comment.

Unicredit's CEO Andrea Orcel has said the bank will provide an update on an ongoing review of its payments business at the end of the first quarter.

Italian payments infrastructure group SIA signed a 10-year contract with UniCredit in 2016 to manage card and shop payments as well as cash withdrawal machines ahead of a being acquired by Nexi, which inherited the contract.

Orcel, who is working to boost the weight of fees in UniCredit's revenues, is trying to manage its payments business in a more unified way across markets, prompting investor concerns that it might seek new partners, in a blow to Nexi.

However, Nexi's finance chief Bernardo Mingrone told analysts in November that the contract did not envisage the possibility of an early break-up.

The contract is "very solid" and Nexi is "very keen to help UniCredit achieve their ambitions in payments, which are growing," the payments company's CEO Paolo Bertoluzzo said at the time.

"Normally if you end up signing a new deal on top of an existing one that is solid it's something that you consider win-win for the company," he told analysts. (Reporting by Alvise Armellini, editing by Gavin Jones)