By Brenna Hughes Neghaiwi and Oliver Hirt

ZURICH, Sept 10 (Reuters) - Credit Suisse will launch a digital banking app in October challenging fintechs like Revolut in the Swiss bank's home market by offering free foreign transactions and fully digital wealth management, the bank said on Thursday.

Credit Suisse's new CSX banking app will offer free online banking from next month, a move it hopes will attract new customers to more lucrative services it will add over coming months, including taking out mortgages, making investments and planning pensions, Switzerland's second-biggest bank said.

"We want to grow with our clients," Swiss head Andre Helfenstein told journalists.

"We thought we needed to do more for young people."

Digital competitors like Britain's Revolut and Germany's N26 have amassed millions of customers and billion-dollar valuations by offering cheap, user-friendly alternatives to traditional banking services. Undercutting incumbents on pricing for foreign exchange, stock trading and money transfers, they are particularly popular with younger customers.

Credit Suisse's move makes it the first major bank to roll out a comprehensive digital package in Switzerland, with a fully digital wealth management service to be added to the app in November.

"CSX falls somewhere in the upper mid-level of what's available," said Ingo Rauser, head of business consultancy Capco, adding basic capabilities rivalled those of online-only "neobanks".

"But, in contrast to the neobanks, Credit Suisse can draw from its full range with digital versions of its investment and pension products in a next step."

Credit Suisse aims to cut costs in its Swiss retail business by closing roughly a quarter of its branches, while bringing in new customers --- particularly in the younger client segment, where it says it has catch-up work to do -- by expanding upon other digital solutions in the market.

That will include "digital bars" where customers can receive advice and connect to specialists via video conference, as well as co-working and event spaces to attract start-ups and entrepreneurs.

Cash withdrawals at ATM machines are not covered by the free version of the app, but clients who do so regularly can reduce costs via a premium version costing 3.95 Swiss francs ($4.34) a month.

That undercuts rival UBS's banking package for general Swiss retail customers, priced from 10 francs a month.

($1 = 0.9105 Swiss francs) (Reporting by Brenna Hughes Neghaiwi; Editing by Michael Shields)