LONDON (Reuters) -Wall Street bank Citigroup's bill for refitting its tower in London has risen to $1.5 billion (1.1 billion pounds), the company told Reuters, highlighting the high costs of overhauling outdated workplaces as businesses seek to attract staff back into the office.

The figure, which Citi is confirming for the first time, is close to the 1.2 billion pounds the bank paid to buy the 42-storey building in the Canary Wharf financial district in 2019.

The bank's budget for the project was increased after it decided to upgrade and occupy more space in the tower to fit an expanded workforce, a Citi executive told Reuters, declining to disclose the original budget. 

Citi said the investment highlighted the company's commitment to Britain, where it employs 14,000 people, including 10,000 in London.

Citi CEO Jane Fraser will visit Britain this week to coincide with U.S. President Donald Trump's state visit, alongside other U.S. business leaders for meetings with Trump and British ministers, the executive said.

The overhaul of the tower at 25 Canada Square includes adding new gardens and amenities, linking teams across multi-level "villages," and upgrading energy and water systems.

The Financial Times reported in January this year that the total cost of the project had topped 1 billion pounds.

Under CEO Fraser, Citi has bucked the wider Wall Street trend by sticking to a hybrid working policy, allowing staff to work up to two days a week from home.

The bank said London-based staff would begin to move in from the second quarter of next year. The project was originally targeting completion in 2025, but Citi said it was on time according to its latest schedule.

After the COVID-19 pandemic led to more working from home, office property prices were pummelled and property owners were forced to rethink older, out-of-town buildings, with business districts like London's Canary Wharf particularly hard-hit. 

Landlord Canary Wharf Group has unveiled plans to overhaul a nearby 45-floor tower being vacated by HSBC.

Citi's rival JPMorgan is assessing options for its own tower in Canary Wharf, including potentially revamping the office, building a new tower nearby, or relocating to central London, Reuters previously reported.

(1 British pound = $1.3556)