LONDON (Reuters) - Britain's HSBC has set up a new unit to tap deals in infrastructure finance and project finance linked to the world's shift to a lower-carbon economy, and hired a former UK politician to lead it, a senior banking executive told Reuters.

HSBC Infrastructure Finance (HIF) will target "a meaningful share" of both in key markets, and incorporate parts of the bank's Global Banking Real Asset Finance team, which includes infrastructure finance, export finance and portfolio management, a memo sent to staff by Greg Guyett, HSBC's CEO of Global Banking & Markets, showed.

The new unit, which will be headed by former UK government minister Danny Alexander, marks a return to 'Project Finance Advisory' for HSBC, which only has a limited capability currently. HSBC hopes HIF will help grow the bank's debt origination and distribution businesses, including by building new public and private sector partnerships.

The move comes as HSBC and other banks increasingly look to align their operations with a corporate commitment to reach net-zero emissions by mid-century, forcing a gradual tightening of lending to high-polluting sectors.

"HSBC has a leading presence in the regions where infrastructure financing and project finance advisory capabilities are critical to enabling a just transition to a low carbon economy," Guyett told Reuters.

The global shift to a cleaner economy will see trillions of dollars spent on building renewable energy and other assets to help cut carbon emissions, as well as adapting existing infrastructure to withstand the impacts of climate change.

Analysis by the OECD, World Bank and United Nations suggests annual investment of $6.9 trillion will be needed by 2030 to ensure infrastructure investment is on track to meet the world's climate and sustainable development goals.

The new unit will work closely with the bank's CMB Infrastructure Finance team, and also oversee its Pentagreen Capital joint venture, a sustainable infrastructure debt unit launched with Singapore investment firm Temasek.

Alexander, a government minister until 2015 and current Asian Infrastructure Investment Bank Vice President for Policy and Strategy, will join HSBC in November and be based in London and will sit on the Global Banking and Markets executive committee, reporting to Guyett. Until his arrival, HIF will be co-led by Alexi Chan and James Dynon.

Guyett said Alexander's appointment would help accelerate efforts to partner with governments, multilateral development banks and companies, "including supporting the UK government's new initiatives".

(Reporting by Simon Jessop and Tommy Reggiori Wilkes; Editing by Susan Fenton)

By Simon Jessop and Tommy Reggiori Wilkes