MILAN, Oct 30 (Reuters) - UniCredit on Monday kicked off a new share buyback for up to 2.5 billion euros ($2.6 billion) and said it had hired Goldman Sachs to carry out the purchases on the market.

Buybacks, which increase shareholder returns on a per share basis as the shares being bought are cancelled, are a key plank of Chief Executive Andrea Orcel's push to drive UniCredit's share price higher.

Orcel has repeatedly said that UniCredit shares are undervalued at their current price of between 5 and 5.5 times forward earnings, arguing the bank's best use of its own excess cash, at least for the time being, is to buy its own shares.

UniCredit last week secured European Central Bank authorisation to bring forward to this year the 2.5 billion euro buyback which relates to 2023 earnings.

It had completed at the beginning of October a second buyback tranche relating to 2022.

UniCredit distributed via buybacks and dividends a total of 5.25 billion euros over 2022 results, with a 40% increase - or an additional 1.5 billion euros - compared with 2021.

While returning to shareholders more than 100% of profits, Orcel has said distribution should be looked at in relation to capital not income.

UniCredit had accumulated excess capital under previous CEO Jean Pierre Mustier, and the reserves have grown further under Orcel, who has focused on businesses that maximise profit in relation to the capital deployed to support them.

The bank generated 9.9 billion euros in capital in the first nine months.

($1 = 0.9471 euros) (Reporting by Valentina Za, Editing by Louise Heavens)